Trump tweeted a photo of the Democratic senator from New York and Russian President Vladimir Putin laughing and holding Krispy Kreme doughnuts. Trump said "we should start an immediate investigation" into Schumer's ties with Russia, calling him a "total hypocrite." He did not accuse Schumer of any specific wrongdoing.
Schumer responded that he would "happily" talk about his contact with Putin. He said it took place in 2003 "in full view" of the press and the public. Schumer then asked if Trump and his team would talk openly about any contact with Russia.
The tweets come a day after Sessions said he would recuse himself from any investigations related to the Trump campaign. Lawmakers raised concerns that he misled senators in his January confirmation hearing about his contacts with the Russian ambassador to the United States, Sergey Kislyak, while he was a U.S. senator and advisor to the Trump campaign.
On Thursday, Schumer called for Sessions to resign, saying he had "weeks" to "correct the record" about his testimony and did not.
Later Friday, Trump slammed House Democratic leader Nancy Pelosi, who also called for Sessions to resign and accused him of perjury. The president said he demands a second investigation into the representative from California, linking to a Politico story that shows a photo appearing to contradict her Friday statement that she never met Kislyak.
Trump has called any developments about links between Russia and his campaign officials a "total witch hunt." He previously asked his first national security advisor, Michael Flynn, to resign after the former general misled top White House officials about his conversations with Kislyak.
Sessions oversees the Justice Department and FBI, which have led investigations into alleged Russian meddling in the 2016 presidential election and any links between Russia and Trump associates. Sessions' recusal will put a deputy in charge of the investigations that relate to the Trump campaign, but it is not entirely clear how broad that recusal will be.
Asked about possible Trump campaign contacts with Russia during his January confirmation hearing, Sessions said he had "been called a surrogate a time or two in that campaign." He said he "did not have communications with the Russians" and was unable to comment on alleged contacts between Trump campaign officials and Russian officials.
On Thursday, Sessions defended his testimony in which he appeared to mislead senators about his contact with Kislyak. He said that, due to the framing of Democratic Sen. Al Franken's question to him, he "focused (his) answer on" whether he met the official in his role as a campaign surrogate, not his position as a then-senator.
"In retrospect, I should have slowed down and said I did meet with one official a couple of times and that was the Russian ambassador," Sessions said Thursday. Sessions said he will send a letter to the Senate Judiciary Committee clarifying his testimony.