JERUSALEM — Sixteen years after he was elected for what was meant to be a four-year term, President Mahmoud Abbas of the Palestinian Authority announced on Friday that presidential and parliamentary elections would be held in the spring and summer.

The announcement appeared to be part of an effort to get the divided Palestinian house in order and project at least a semblance of unity as the Palestinian Authority prepares to repair ties with Washington and the incoming Biden administration after a disastrous few years of discord and disconnect under President Trump.

The presidential decree stated that the voting for the long-defunct Palestinian Legislative Council would take place on May 22, followed by presidential elections on July 31.

Mr. Abbas, 85, the leader of Fatah, the mainstream Palestinian party, was last elected to office in early 2005 after the death of his predecessor, Yasir Arafat.

Analysts said they believed that Mr. Abbas was now seeking to renew his legitimacy in the eyes of the international community, especially with the imminent arrival of President-elect Joseph R. Biden Jr. in the White House, which they said Mr. Abbas hoped would herald a return to negotiations with Israel.

“He doesn’t want to hear from anyone that he doesn’t represent the Palestinian people and that he’s not in control of Gaza,” said Jihad Harb, an expert on Palestinian politics.

The last time the Palestinians went to the polls, it did not end happily.

In 2006 a rival party representing Hamas, the Islamic militant group, trounced Fatah in elections for the Legislative Council, leading to a year and a half of uneasy power sharing.

The United States and much of the West refused to work with the unity government because Hamas, which they considered a terrorist organization, would not accept international demands such as renouncing violence and recognizing Israel’s right to exist.

A brief civil war between the two groups ensued in the coastal territory of Gaza. It ended in June 2007, with Hamas seizing control there after routing forces loyal to Mr. Abbas and confining his authority to parts of the occupied West Bank.

Mr. Abbas responded by forming an emergency government based in the West Bank, but Hamas officials refused to recognize it. The political and geographical schism, as well as the collapse of a series of reconciliation agreements, has since stymied any semblance of a functioning democratic process.

A behind-the-scenes succession race has long been underway in the Palestinian Authority, and Mr. Abbas said a few years ago that he did not want to run again for the presidency.

But there was no hint on Friday he intended to step down, and the election announcement was greeted with a degree of skepticism because Mr. Abbas has in the past announced plans for elections that never took place.

In February 2011, for example, Mr. Abbas announced that elections would be held in September of that year, but Hamas rejected the idea and they were called off.

Hamas welcomed Mr. Abbas’s new decree, saying in a statement that it was keen to make the elections “successful.” It added that work was needed to create an atmosphere for free and fair elections, and that Hamas had shown what it called great flexibility in recent months “out of a belief that the decision belongs to the people.”

Still, some analysts expressed significant doubts about whether Mr. Abbas was interested in ultimately allowing the elections to go ahead, and the two rival Palestinian factions have not explained publicly how they will hold elections while the West Bank and Gaza are ruled by the separate groups.

“These decrees are just a maneuver to buy time,” said Ghaith al-Omari, a former adviser to Mr. Abbas and a fellow at the Washington Institute for Near East Policy. “The deep suspicion between Abbas and Hamas still holds, and the reasons that have prevented elections in the past are still unchanged.”

Nabil Amr, a veteran figure in Fatah and a former information minister, described the elections decree as “a preliminary practical step.” But he warned that Palestinians who stood to lose from the elections could work to impede them. “There are Palestinians whose privileges will be taken away if the elections are held, so they will oppose it,” he said.

It remains unclear whether Hamas will accept the authority of the court that Mr. Abbas plans to establish to adjudicate election disputes, how freely candidates will be able to campaign and whether Mr. Abbas will agree to allow Hamas’s security forces, which he considers illegitimate, to secure polling booths in Gaza.

Israel may also decide to bar Palestinians from voting in Israeli-annexed East Jerusalem — a potential obstacle that Mr. Abbas has previously said would prevent elections from going forward.

Azzam al-Ahmad, a member of the Fatah Central Committee, said Palestinian officials would ask Israel to refrain from “placing impediments” on the Palestinians voting in East Jerusalem, but added that he expected the Israelis would do so regardless.

Both Hamas and Fatah are convinced that they need to hold to elections, said Ghassan Khatib, a political scientist at Birzeit University in the West Bank, but it was unclear what kind of an election it would be.

“Will it be a real election, or will it be a staged election that will renew the legitimacy of the same old guards?” he said. “My fear is that it’s a kind of election that is not going to make any change — except that it will give the superficial impression that we are more legitimate now.”

More broadly, he wondered how the election could be pulled off after such a long and bitter split.

“How are we going to conduct an election where the political system is divided completely into two separate election systems, two judicial systems, two security apparatuses, two everythings?” Mr. Khatib said. “That’s the question everyone is asking.”

Patrick Kingsley contributed reporting from Jerusalem and Mohammed Najib from Ramallah, West Bank.