The U.S. Senate on Tuesday, March 28 overwhelmingly backed the expansion of NATO to allow Montenegro to join the alliance, hoping to send a message that the United States will push back against Russian efforts to increase its influence in Europe, Reuters says.

The long-delayed vote was 97-2 in favor of Montenegro's accession to the North Atlantic Treaty Organization. That was well above the two-thirds majority needed in the 100-member Senate to ratify Montenegro's membership.

There was no immediate confirmation of whether President Donald Trump would formally deposit the instrument of ratification, the last step in the U.S. ratification process.

However, his administration had supported NATO membership for the tiny Balkan nation, one of Europe's smallest, despite Trump at times criticizing the alliance as he campaigned for president last year.

While campaigning, Trump accused other NATO members of failing to pay their fair share while adopting a conciliatory tone toward Russia. But as president, Trump has pledged his support for the alliance.

Reuters reported last week that Secretary of State Rex Tillerson wrote to the leaders of the Senate this month to say Montenegro's membership in NATO was "strongly in the interests of the United States."