Bob Dole, the long-time Kansas senator who was the Republican nominee for president in 1996, has died. He was 98.

In a statement on Sunday, the Elizabeth Dole Foundation – founded by Dole’s wife, a former North Carolina senator and cabinet official – said: “It is with heavy hearts we announced that Senator Robert Joseph Dole died earlier this morning in his sleep. At his death at age 98 he had served the United States of America faithfully for 79 years.”

In late February, Dole announced that he had advanced lung cancer and would begin treatment. Visiting him, Joe Biden called Dole his “close friend”. The two men were in the Senate together for 23 years.

On Sunday, Biden said: “We picked up right where we left off, as if it were only yesterday that we were sharing a laugh in the Senate dining room, or debating the great issues of the day, often against each other on the Senate floor.

“I saw in his eyes the same light, bravery and determination I’ve seen so many times before in the Senate. Though we often disagreed, he never hesitated to work with me or other Democrats when it mattered most.”

Citing Dole’s work on the Americans with Disabilities Act, the Social Security Commission and in creating a public holiday in honour of Martin Luther King – “a bill that many in his own caucus opposed” – Biden called Dole “an American statesman like few in our history, a war hero and among the greatest of the greatest generation”.

“To me,” he said, “he was also a friend whom I could look to for trusted guidance, or a humorous line at just the right moment to settle frayed nerves.”

The House speaker, Nancy Pelosi, ordered flags at the Capitol flown at half-staff.

Born in Russell, Kansas, in 1923, Dole left college to serve in the US infantry in the second world war, suffering serious wounds in Italy and winning a medal for bravery.

His wounds cost him use of his right arm but he entered state politics and soon became a Republican power-broker, representing Kansas in the US House from 1961 to 1969 and in the Senate until 1996. He had spells as chairman of the Republican National Committee and as Senate minority and majority leader.

In 1976 he was the Republican nominee for vice-president to Gerald Ford, in an election the sitting president lost to Jimmy Carter. Famously, in a debate with Walter Mondale Dole said America’s wars in the 20th century had been “Democrat wars”.

Mondale said Dole had just “richly earned his reputation as a hatchet man”. Dole denied saying what he had just said, then backed down. He eventually acknowledged going too far.

“I was supposed to go for the jugular,” he said, “and I did my own.”

He pursued the Republican nomination in 1980 and 1988 and finally won it in 1996, at the age of 73 and two decades after being on the ticket.

That put him up against Bill Clinton, a formidable campaigner seeking a second term. Against the backdrop of a booming economy, the Democrat won with ease, by 379–159 in the electoral college and by nine points in the popular vote, the third-party candidate Ross Perot costing Dole support on the right.

On Sunday, Clinton said of Dole: “After all he gave in the war, he didn’t have to give more. But he did. His example should inspire people today and for generations to come.”

Dole received both the Presidential Medal of Freedom and the Congressional Gold Medal, the highest US civilian honours.

In December 2018, amid ceremonies in honour of the former president (and Dole’s rival) George HW Bush, Dole appeared before Bush’s casket in the Capitol Rotunda. As an aide lifted him from his wheelchair, Dole steadied himself and saluted.

In the Trump years and after, Dole came widely to be seen as a figure from another time in Republican politics. On Sunday, the political consultant Tara Setmeyer, a member of the anti-Trump Lincoln Project, tweeted: “I cast my first ever vote for president for Bob Dole in 1996. A war hero with a sharp sense of humor … another piece of a once respectable GOP gone.”

But Dole remained a loyal Republican soldier. This summer, he told USA Today that though Donald Trump “lost the election, and I regret that he did, but they did”, and though he himself was “sort of Trumped out”, he still considered himself “a Trumper”.

On Sunday, Trump called Dole “an American war hero and true patriot for our nation”.

In the same USA Today interview, Dole called Biden “a great, kind, upstanding, decent person”, though he said he leaned too far left.

He also said: “I do believe [America has] lost something. I can’t get my hand on it, but we’re just not quite where we should be, as the greatest democracy in the world. And I don’t know how you correct it, but I keep hoping that there will be a change in my lifetime.”

On Sunday the Senate Republican leader, Mitch McConnell, a fiercely partisan Washington warrior who many on the left hold responsible for America losing its way, said: “Whatever their politics, anyone who saw Bob Dole in action have to admire his character and his profound patriotism. Those of us who were lucky to know Bob well ourselves admired him even more.”

• The Associated Press contributed to this report