The Republican majority in the Senate on Thursday quashed a measure to limit the Trump administration’s ability to wage war against Venezuela, boosting the risk of an escalation in the weeks ahead.

By a 51-49 vote, senators rejected the resolution from Sens. Tim Kaine (D-Va.), Adam Schiff (D-Calif.) and Rand Paul (R-Ky.).

Paul and Lisa Murkowski (R-Alaska) provided the only GOP votes for the legislation to terminate military operations within or against Venezuela without specific authorization from Congress. The vote came amid many top Trump administration officials pushing for U.S. military involvement to remove Venezuela’s autocratic ruler, Nicolas Maduro, from power.

“We should not be in a war without Congress,” Kaine said ahead of the vote.

President Donald Trump reportedly has not made a final decision on directly attacking Venezuela. However, he has approved CIA operations there, along with a major military build-up off the country’s coast and a campaign of U.S. strikes against boats in the Caribbean near Colombia, Venezuela and off western South America that has killed at least 66 people. The administration claims the effort is targeting drug trafficking, but has not provided proof of criminality by those killed or evidence for its claim that Maduro oversees a major narcotics scheme that is harming Americans. Opposition to Maduro and to his ally Cuba has long been a fixation for some Republicans, notably Secretary of State and acting national security adviser Marco Rubio.