White House officials on Wednesday declined to say if President Biden will visit the Ukrainian border this week during a trip to Poland — but indicated it was a possibility by citing security concerns for the lack of information.

Reporters aboard Air Force One pointed out during a press gaggle that there’s a significant gap in Biden’s schedule on Friday as he visited Europe to rally allies against Russia’s invasion of Ukraine.

“Clearly we will give more guidance on what Friday will look like. But for security purposes, we just want to keep it more broad and not go into details,” White House deputy press secretary Karine Jean-Pierre said.

Biden will stop first in Belgium for Thursday meetings between Biden and US allies before flying to Poland the next day to discuss Western aid for Ukraine and efforts to care for more than 3.5 million refugees who fled Russia’s invasion.

White House national security adviser Jake Sullivan also sidestepped Biden’s plans for Friday before he meets Saturday in Warsaw with Polish President Andrzej Duda.

“Can you talk a little bit about Friday? There’s obviously a big gaping hole in the president’s schedule. Is he gonna go close to the border?” a reporter aboard Air Force One asked Sullivan.

Sullivan coyly replied, “I’ll let Karine talk to you about Friday when the time is right.”

The trip is Biden’s third overseas as president. The first stop will feature a speech to members of the NATO alliance on Thursday as well as to a meeting of G7 leaders — a group that includes the six most economically powerful NATO economies and Japan.

Biden’s trip followed a last-minute health scare when press secretary Jen Psaki tested positive for COVID-19 on Tuesday after attending two meetings with Biden on Monday.

Jean-Pierre said Biden tested negative for the virus on Tuesday and would get tested again before entering Poland and then again before returning to the US from Poland in compliance with a CDC rule that requires US citizens to test negative before returning from abroad. She did not say what would happen if there’s a positive result.

“There’s no change to the president’s testing cadence during his travel because he was not a close contact. He will be tested throughout the trip in alignment with the various entry and departure requirements for the countries he will be visiting,” she said. “For example, for context here, there’s no testing entry requirement for Brussels. There will be a testing requirement for Warsaw and an exit requirement for return to the US.”