Republicans appeared to undercut President Donald Trump in a key part of the annual National Defense Authorization Act, according to a new report.

The recently released NDAA, a 3,000-page bill that directs more than $900 billion in spending on various defense programs, reflects "bipartisan concerns" that the Trump administration could significantly reduce the number of American troops in Europe, Politico reported on Sunday. The report adds that the language "stands in stark contrast" to Trump's isolationist national security strategy.

In response, Republicans added language to the bill, which Politico described as a "compromise," requiring the Department of Defense to meet specific metrics before troops can be withdrawn.

"Republicans, led by Senate Armed Services Chair Roger Wicker (R-MS) and House Armed Services Chair Mike Rogers (R-AL), broke with the Trump administration, arguing that troop reductions — such as a recent decision to remove a rotational Army brigade from Romania — would invite aggression from Russia," Politico reported.

"The final bill blocks the Pentagon from reducing the number of troops permanently stationed or deployed to Europe below 76,000 for longer than 45 days until Defense Secretary Pete Hegseth and the head of U.S. European Command certifies to Congress that doing so is in U.S. national security interests and that NATO allies were consulted, along with assessments of the impacts of doing so," the report added.

The House of Representatives released their version of the NDAA on Sunday night. Lawmakers are expected to vote on the bill as early as this week.

Read the entire report by clicking here.