WASHINGTON — A provision in the Senate Armed Services Committee’s new defense policy bill would make it tougher for President Donald Trump to pull the United States out of NATO, sending a strong sign of bipartisan support for the alliance.

The $750 billion bill, which passed the committee on Wednesday, includes language to bar funding for a year for a withdrawal from Europe, if the U.S. initiates an exit from NATO. The provision seems designed to hem in Trump, whose rhetoric has sent mixed messages about America’s commitment to the 29-nation alliance.

The panel’s Readiness Subcommittee ranking member, Sen. Tim Kaine, D-Va., sponsored the language and said Thursday that it was embraced unanimously and on a bipartisan basis.

To answer a report he had floated a NATO withdrawal, Trump said in January he was “100 percent” behind the alliance. Critics, however, have focused on his false claims NATO allies owe the United States money, his long history of jabs at NATO members for missing military spending targets and a threat to withdraw during the 2018 NATO summit.

“We’re confused about their intent,” Kaine said of the White House on NATO, adding, “This bill says if the president unilaterally tries to pull out, no funds can be expended to remove troops for a year. That gives Congress the opportunity to debate and overturn a decision if we think it’s unwise.”

Some Republicans, who have credited Trump’s pressure tactics for boosting NATO spending, may not agree that the president is on the verge of leaving the alliance.

Sen. Thom Tillis, R-N.C., the SASC Personnel Subcommittee chair and co-leader of the recently revived NATO Observer Group, offered a mixed assessment of the bill language, which he said could give credence to a “false narrative” that the U.S. is leaving NATO.

“Our NATO partners need to know our president has no intention of withdrawing from NATO. He does have every intention of making [allies] live up to their obligations,” Tillis said.

“[The Kaine provision is] a matter of making sure our partners understand that we’re committed to them," Tillis said, "but it’s not like this is something we as members of the Senate Armed Services Committee said we had to do because we’re concerned about a precipitous withdrawal.”