President Joe Biden and Germany's leader sought to put on a united front Monday at the White House, but one key sticking point appeared to remain despite their pledges of unity: The future of the Nord Stream 2 gas pipeline.

At the White House and in an interview on CNN's "The Lead with Jake Tapper," German Chancellor Olaf Scholz revealed a distinct gap between himself and his American counterpart on the massive pipeline. During a news conference after an Oval Office meeting, Biden was explicit the project wouldn't go forward if Russia invades Ukraine. It's the stance he and US officials have taken for weeks, and has been a key point of discussion with the new Scholz government, according to senior administration officials.

But Scholz himself refused to even name the project during the news conference, and declined to commit to ending the pipeline if an invasion moves ahead -- a stance causing problems for his foreign minister during a visit to Ukraine. In the interview with CNN, Scholz repeated his vow to remain aligned with the US, though again wouldn't clarify his intentions for the Nord Stream project.