Still, news of the impeachment inquiry persisted then, as it did this week.

On each leg of this week’s trip, Mr. Pence stayed in close contact with the president behind the scenes. With their respective airplane televisions tuned to Fox News, they exchanged multiple phone calls each day, in part to compare notes on the unfolding trial.

Publicly, both men have addressed the matter of impeachment with blustery interviews that downplay their collective involvement in the interactions that form the heart of the case against Mr. Trump.

In recent days, Lev Parnas, an associate of Mr. Trump’s personal lawyer, Rudolph W. Giuliani, has said in interviews that Mr. Trump canceled plans for Mr. Pence to attend the inauguration last year of President Volodymyr Zelensky of Ukraine, after the Ukrainians declined to announce a corruption investigation into the family of former Vice President Joseph R. Biden.

On Friday, Mr. Pence denied knowledge that the Trump administration had engaged in a pressure campaign against Ukraine, withholding aid or a White House visit for Mr. Zelensky in an exchange for an investigation.

“But what I’ve said over and over again,” he said, “is I was never aware of the allegations that there was some pressure campaign for investigations against the Bidens that was underway until those matters became public.”

Mr. Pence has contended that he does not know Mr. Parnas — “I don’t recall ever having met Mr. Parnas,” he said again on Friday — and those claims prompted Mr. Parnas’s lawyer to release video of his client meeting the vice president.

And when Mr. Pence was asked about leaked audio of Mr. Trump saying “take her out,” in an apparent reference to the American ambassador to Ukraine, Marie L. Yovanovitch, Mr. Pence defended the president, who removed her from her post last year. The tape, he said, would confirm only “that the President had concerns, and in his authority this president made a decision.”