The procedural step, which advanced on a 97-2 vote, sets up a final approval in the chamber in the coming days.
President Donald Trump’s administration has encouraged lawmakers to back the small Balkan nation’s bid.
“It is strongly in the interests of the United States that Montenegro’s membership in NATO be ratified,” Secretary of State Rex Tillerson told Senate leaders in a March 7 letter.
To date, 25 of NATO’s 28 members have ratified Montenegro’s accession, a country of 620,000 people seen as a geostrategic ally.
The North Atlantic Treaty Organization holds its summit on May 25 in Brussels, where Trump will use the opportunity to reaffirm Washington’s strong commitment to the alliance, according to the White House.
The Kremlin is opposed to Montenegro’s accession, calling it a “provocation” that would reinforce the pro-Western military alliance’s presence in the Balkans.
The US vote comes days after a Montenegrin special prosecutor accused “Russian state bodies” of involvement in an alleged coup plot during Montenegro’s election last October.
Moscow branded the accusation “absurd.”
Russia also stands accused of interfering in the US presidential election last year, when US intelligence agencies say it leaked hacked emails that damaged Democrat Hillary Clinton’s campaign.
Senator John McCain, among the move’s strongest backers, framed Montenegro’s accession as nothing less than a “test” of resolve against Russian President Vladimir Putin.
“He attempted a coup” to overthrow the freely-elected Montenegro government,” McCain told the Senate Monday.
“That coup failed. But I can assure that if we turn down Montenegro, it will not remain the democracy that it is today.”
Senator Marco Rubio weighed in saying the Senate is “sending a clear message to Vladimir Putin that we will not accept the establishment of Russia’s sphere of influence over countries that desire to ally themselves with the free and democratic community of nations.”
As with all international treaties, a two-thirds majority is required for final Senate approval. Success is highly likely.
Republicans Rand Paul and Mike Lee voted against the measure.
Paul warned Washington against spreading itself too thinly when its military is involved in Iraq, Syria, Libya and Yemen, and said Montenegro in NATO will antagonize Russia while doing “nothing” to advance US national security.
PTI