Ukraine’s sense of urgency in obtaining the fighter jet reflects concerns about the war against Russia, but also the political calendar in the West. But training pilots and support crew is a lengthy process.The F-16 fighter jets would not be delivered to Ukraine until next year, but that did not dissuade President Volodymyr Zelensky from hopping into one last week in the Netherlands — one stop on a European tour to collect commitments to donate the warplane as quickly as possible.There he was in Denmark, praising the government for “helping Ukraine to become invincible” with its pledge to send 19 jets. In Athens, he said Greece’s offer to train Ukrainian pilots would “help us fight for our freedom.” Within days of returning to Kyiv, Mr. Zelensky had secured promises from a half-dozen countries to either donate the jets — potentially more than 60 — or provide training for pilots and support crew.“It is important and necessary,” Prime Minister Jonas Gahr Store of Norway told Mr. Zelensky in Kyiv, announcing that his government would provide an undetermined number of the jets — probably 10 or fewer — in the future.It was a remarkable victory lap for a sophisticated attack aircraft that even Ukraine’s defense minister has acknowledged is unlikely to perform in combat until next spring — and then only for the few pilots who can understand English well enough to fly it. With Ukraine’s counteroffensive grinding ahead slowly this summer, Mr. Zelensky’s airy announcements of securing the F-16s signal a tacit acknowledgment that the 18-month war in Ukraine will likely endure for years to come.They were also a palpable signal of Mr. Zelensky’s fixation on a fighter jet that is faster, more powerful and more versatile than existing Ukrainian aircraft, but that has spurred debate over how substantially it can advance Kyiv’s immediate war effort. The F-16 has both offensive and defensive capabilities — it can be launched within minutes and is equipped to shoot down incoming missiles and enemy aircraft.People gathered outside the Danish Parliament during a visit by Mr. Zelensky. Mads Claus Rasmussen/EPA, via ShutterstockUkraine has adamantly insisted the planes would make a significant difference, though American officials have long maintained that tanks, ammunition and most of all, well trained ground troops are far more important in what is, right now, primarily a ground war. The Western warplanes are costly and it could take years to train and field enough pilots to provide sufficient air cover.As it presses for the fighter jets, Ukraine also senses a ticking political clock, current and former officials in Kyiv and Washington said. Mr. Zelensky appears driven to get as many of the F-16s as possible delivered before elections in Europe and the United States, which could bring a change of heart in the governments that have promised the planes.The Netherlands, for example, has pledged to give Ukraine as many as 42 F-16s it is phasing out of its air force; it will hold parliamentary elections this November. The larger concern, though, is the United States, where Republican support for sending tens of billions of dollars in aid to Ukraine is dropping. Former President Donald J. Trump, the frontrunner for the Republican nomination, said in July he would push Mr. Zelensky into peace agreements by telling him “no more — you got to make a deal.”“The American political uncertainties are very much on the minds of Ukrainians, and all of Europe,” said Senator Richard Blumenthal, Democrat of Connecticut, who met with Mr. Zelensky in Kyiv just as the Ukrainian president was returning from his F-16 tour last week. “One of the objectives here, clearly, is to lock in commitments as clearly and unequivocally as possible.”Mr. Zelensky, left, met with Senators (from left) Richard Blumenthal, Elizabeth Warren and Lindsey Graham in Kyiv earlier this month. Ukrainian Presidential Press Service/via ReutersHe said Mr. Zelensky did not directly discuss next year’s U.S. elections during their meeting, which also included Senators Lindsey Graham, Republican of South Carolina, and Elizabeth Warren, Democrat of Massachusetts, and was held in an underground room at the Intercontinental Hotel in Kyiv immediately after an air raid alarm. But, he said in a telephone interview, the more that can be delivered before November 2024, “the more that air support is not threatened by the vagaries of American politics.”So far, the Biden administration has not committed to sending Ukraine any F-16s from its own fleet, although it announced last week that it would train pilots at air bases in Texas and Arizona starting in September.It is expected to take at least four months to train Ukraine’s pilots on aircraft more advanced than what they are used to flying, and on tactics and weapons they are not used to employing. It could take even longer to teach them enough English to understand training manuals and to communicate with air traffic controllers and instructors. The avionics on the planes, including the buttons, are in English.There is another wrinkle in plans to deliver the planes. The United States must give approval before other countries can send American-made jets to Ukraine. The Biden administration has signaled to Denmark, Norway and the Netherlands that it will allow the transfers, but a new president could reverse those case-by-case agreements if delivery has not yet been completed, according to a U.S. official.Several officials cited in this article spoke on condition of anonymity, saying they were not authorized to discuss the issue publicly.A former senior Biden administration official said that Mr. Zelensky’s spate of F-16 announcements was also likely intended to lock in Western commitments in the event that a sluggish counteroffensive erodes political support among allies.Ukrainians firing on Russian positions from an infantry fighting vehicle. Tyler Hicks/The New York TimesMr. Zelensky’s sense of urgency has been unmistakable. In addition to his diplomatic forays, he mentioned the F-16s at least eight times during his nightly addresses in August, predicting that their presence in Ukrainian skies will vanquish Russian forces. Officials in Kyiv have even used the death last week of one of their famed pilots in a training accident to underscore that Ukraine needs the jets to win. Part of the jets’ appeal is that they are in plentiful supply. Many European air forces have F-16s and are getting rid of them to transition to the even more advanced F-35. So they exist in ample numbers with a built-in Western repair and supply chain, and training programs that can support them years into the future.However, the immediate hurdle to fielding the F-16s that have been pledged is not the actual jets, but the shortage of trained English-speaking Ukrainian pilots and support crew to fly and maintain them.A former senior U.S. Air Force officer said it takes between 8 to 14 support personnel to maintain, fuel and support each F-16, depending on how many bases the jets operate from. It will take roughly as long to train the support crews as the pilots, the officer said.So far, American officials have said, only eight Ukrainian pilots are sufficiently fluent in English and experienced in flying combat aircraft to have started training on the F-16s in Denmark. At least 20 other pilots are starting English-language instruction in Britain. Even Ukrainian pilots skilled at flying the Soviet-era MiG-29 jets that make up much of Kyiv’s current fleet would have to learn to navigate the F-16s’ “hands-on throttle and stick” or “HOTAS” technology; that’s a system that would let them shift from bombing targets on the ground to engaging in air-to-air combat without taking their hands off the controls.The system makes it easier to navigate between the two targets than on a MiG-29, but it still takes time to learn.“That all is going to take time and that probably is not going to happen before the end of the year,” Gen. James B. Hecker, the top U.S. air commander in Europe, told reporters at George Washington University’s Defense Writers Group on Aug. 18.One U.S. adviser said Ukraine will probably deploy the initial F-16s as soon as the pilots are certified to fly, in a range of defensive and offensive combat missions. Given the advanced weapons the F-16s will carry, just having them deployed, even in a niche capacity, could force Russia to dedicate valuable resources to monitor and counter them, the adviser said.Pro-Ukraine demonstrators called on President Joe Biden to send F-16 jets to Ukraine in a protest outside the hotel where he stayed in Warsaw in February. Aleksandra Szmigiel/ReutersStill, their effectiveness would still be limited by Russian air defenses and advanced fighters developed to specifically combat NATO aircraft such as the F-16.“In the short term they’ll help a little bit, but it’s not the silver bullet,” General Hecker said.U.S. officials say the F-16s are important for other reasons. Their arrival will boost Ukrainian morale and signal the shift of Ukraine’s air force to a NATO-caliber fleet. That sends an important deterrent message to Russia, to stave off future attacks from Moscow once this war is over, U.S. officials say.U.S. officials have repeatedly stated that providing Ukraine with F-16s is more about the future than the present.“Putin’s strategy is clearly to outlast, or out-wait, America and count on it lacking the will or the arms to continue,” Mr. Blumenthal said.He added: “There is a kind of gap, so to speak, between the victory lap of accepting the planes and the actual delivery. But the goal is to close that gap as quickly as possible and get F-16s on the battlefield.” More