Gregory Korte

USA TODAY

WASHINGTON — President Obama called Donald Trump’s admiration of Russian President Vladimir Putin “unprecedented,” accusing formerly hard-line Republican politicians — including Trump's running mate, Mike Pence — of softening on Russia.

"Mr. Trump rarely surprises me these days," Obama said in a press conference with Italian Prime Minister Matteo Renzi at the White House Tuesday. "I am much more surprised and troubled by the fact that you have Republican officials — who historically have been adamantly anti-Russian and in fact have attacked me for even engaging them diplomatically — now supporting, and in some cases echoing, his positions. It's quite a reversal."

And Obama pushed back against Trump's allegations that the election is "rigged."

"I have never seen in my lifetime, or in modern political history, any presidential candidate trying to discredit elections and the elections process before even elections have taken place. It's unprecedented," Obama said. "I'd invite Mr. Trump to stop whining and try to make his case to get votes."

Rigged election? A chorus of complaint from Team Trump

Obama's said his comments on Trump were more "subdued" than he would be on the campaign trail, since they came during a state visit with the Italian Prime Minister. But the subject of Trump seemed inevitable, as even Renzi acknowledged that Americans were more interested in the Nov. 8 U.S. election than in Italian politics. "And so are we, I might add."

In a private meeting in the Oval Office, Obama and Renzi said they discussed climate issues, economic growth, disaster response, Syria and the migrant crisis in Europe. Later Tuesday, they're scheduled to have a state dinner on the South Lawn of the White House — Obama's last as president. "First duty, then pleasure," Obama said.

In a formal welcoming ceremony on an unusually warm October morning, Obama and Renzi reaffirmed the long history of friendship between the two countries. Obama said that the founding fathers "drew inspiration from Cincinnatus, Cicero, Cato." Renzi noted that America was named for Italian explorer Amerigo Vespucci, and thanked the young Americans who "sacrificed their lives to give freedom back to Italy" during World War II.

But with three weeks to go until the election to succeed Obama, the two leaders also made remarks that can only be interpreted as thinly veiled commentary on the candidacy of Donald Trump.

"America was built by immigrants. America is stronger because of immigrants. America is great because of immigrants," Obama said.

Renzi spoke of building "bridges, not walls," and appealed for world leaders to look to the future, and not just the past.

"There are a lot of people who think politics is only about screaming, fighting each other, creating division. You’re different, Mr. President," Renzi said. "We're different."

Every president since Lyndon Johnson has hosted a state dinner for an Italian leader. Tuesday's event is being catered by celebrity chef Mario Batali with a musical performance by Gwen Stefani.

What are Michelle Obama's favorite foods? State dinner guests will find out.