Deputy Attorney General Rod Rosenstein visited the White House on Tuesday for what was described as "routine meetings."

Rosenstein, who is overseeing Special Counsel Robert Mueller's investigation of possible Trump campaign collusion with Russia, did not meet with President Trump, White House Press Secretary Sarah Sanders said in a statement.

Sanders did not identify the officials with whom Rosenstein met, or the topics they discussed.

Rosenstein's trip to the White House came a day after Trump shared a stage with Russian President Vladimir Putin in Finland and called Mueller's probe "a total witch hunt" and said "it’s ridiculous what’s going on with the probe."

Key Trump allies in Congress, including Reps. Mark Meadows, R-N.C., and Jim Jordan, R-Ohio, reportedly are preparing to introduce legislation to impeach Rosenstein.

[More: Trey Gowdy dismisses a House effort to oust Rod Rosenstein: 'Impeach him for what? No']

Rosenstein is overseeing Mueller's work because Attorney General Jeff Sessions recused himself due to the role he had played on Trump's 2016 campaign.