President Donald Trump has raised the bar in his war with Democrats over allegations related to Russia's alleged meddling in the 2016 presidential election.

On Friday, Trump posted a photo to his personal Twitter account of Senate Minority Leader Chuck Schumer (D-N.Y.) and Russian President Vladimir Putin smiling together over coffee and doughnuts.

"We should start an immediate investigation into @SenSchumer and his ties to Russia and Putin. A total hypocrite!" Trump tweeted.

Without missing a beat, Schumer responded to Trump on Twitter, saying he would gladly talk about the photo, which was taken "in full view of the press."

"Happily talk re: my contact w Mr. Putin & his associates, took place in '03 in full view of press & public under oath. Would you & your team?" Schumer said.

The photo of Schumer and Putin was taken during the opening of a Lukoil gasoline station in the Chelsea neighborhood of Manhattan on Sept. 26, 2003. The gas station has since closed.

"You couldn't get more of an open and transparent meeting," said Schumer's former press secretary, Stu Loeser, who helped organize the photo op with Putin.

Loeser said the meeting, which lasted about 15 minutes, was pitched to hundreds of reporters. Putin got out of his car, met the owner of the gas station and then went into the shop, where the now-famous photo of Schumer and Putin was taken -- all of which happened in front of reporters, he said.

"I think like Chuck said in his response, this event took place in full view of the press and public," Loeser said. "I can't speak to the president and his team. The other meetings in question, I don't think, were set up in the same way."

Schumer and other Democrats have been thoroughly outspoken about getting to the bottom of the Trump campaign's possible ties to Russia during the 2016 presidential race. 

Late last year, U.S. intelligence agencies had concluded that Russia hacked Democratic emails during the election cycle and leaked them in order to sway voters in Trump's favor -- allegations that Russia denies.

The Twitter spat erupted one day after Attorney General Jeff Sessions recused himself from any investigations regarding the Trump campaign's possible contacts with Russia.

The move came after it was revealed that Sessions, a former U.S. senator and senior aide in Trump's campaign, had met with Russia's ambassador twice last year. Sessions failed to mention those meetings during his confirmation hearing, during which Sen. Al Franken had asked if he had any contact with Russians while working on the president's campaign.

During a news conference on Thursday, Sessions said he was acting solely as a senator during the meetings and did not discuss the Trump campaign.

The Justice Department confirmed the two meetings, saying they were in Sessions' capacity as a member of the Senate Armed Services Committee and there was nothing untoward about them.

Despite calls for his resignation from Democrats who were not satisfied with his recusal, Trump defended Sessions in a series of tweets on Thursday night.

"Jeff Sessions is an honest man. He did not say anything wrong. He could have stated his response more accurately, but it was clearly not intentional," Trump wrote.

Many Democrats, however, believe Sessions lied under oath during his confirmation hearing. House Democratic leader Nancy Pelosi repeated a call for Sessions to resign on Thursday, saying "his narrow recusal and sorry attempt to explain away his perjury" were totally inadequate.

Pelosi was also unable to escape Trump’s Twitter wrath on Friday.

“I hereby demand a second investigation, after Schumer, of Pelosi for her close ties to Russia, and lying about it,” Trump said after deleting two other versions of the tweet with the word “hereby” spelled wrong.

Trump included a link to a Politico article that offers photo evidence of Pelosi sitting across from current Russian ambassador Sergey Kislyak in 2010, despite that the lawmaker claimed to have never met him.

In case you were wondering, the doughnuts Schumer and Putin were smiling over were Krispy Kreme, the senator said in a follow-up tweet.

-With Reuters