Fifteen Democratic and Republican US senators introduced a bill on Thursday that would bar any US president from withdrawing from the NATO military alliance without Senate approval, Reuters reported.

The bill, seen by Reuters, is a new version of a similar measure that passed the Senate Foreign Relations Committee in December 2019, but was never considered by the full Senate, then controlled by Republicans.

If a president attempts to leave NATO without Senate approval, the bill would prohibit funding for such a move and authorizes the Congressional Legal Counsel to challenge the administration in court.

"This bill expresses clear congressional support for the continuing value of NATO and clarifies that no President acting alone can sever the bonds of the alliance," Senator Tim Kaine, one of the measure's lead sponsors, said in a statement.

"With Moscow’s growing subversive aggressions, we must ensure no U.S. President withdraws from NATO without the advice and consent of the Senate," Republican Senator Marco Rubio, the bill's other lead sponsor, said in a statement.

The bill's sponsors are optimistic about its chances of passing and becoming law, given President Joe Biden's recent expressions of strong support for the alliance.