NATO Secretary-General Jens Stoltenberg welcomes U.S. Vice President Mike Pence at the NATO headquarters in Brussels, Belgium, Feb. 20, 2017.
NATO Secretary-General Jens Stoltenberg welcomes U.S. Vice President Mike Pence at the NATO headquarters in Brussels, Belgium, Feb. 20, 2017.

U.S. Vice President Mike Pence voiced staunch American support Monday for the NATO military alliance with Europe, but said that too many of the European countries "still lack a clear and credible path" to increasing their defense spending to pay for the seven-decade-old partnership.

Standing at NATO headquarters in Brussels, Pence noted that only the U.S. and four other countries among the alliance's 28 members are meeting their requirement to spend 2 percent of their national economies on defense.

"We intend to increase our defense spending. America will do our part," Pence declared of the new U.S. administration under President Donald Trump. But he added, "It is time for action, not words" by the 23 countries that have not met the minimum 2 percent threshold.

WATCH: Pence remarks about NATO

Pence won support from NATO Secretary General Jens Stoltenberg, who said, "I fully support the importance of burden sharing. The good news is we are moving in that direction."

He said Germany, with Europe's biggest economy, has increased its defense funding and that some other countries -- including Latvia, Lithuania and Romania -- could meet the 2 percent figure soon or  "within a year or two." The five that already spend 2 percent on defense are Greece, Poland, Estonia, Britain and the U.S.

"All allies have committed to ... the defense investment pledge, meaning to stop the cuts and to start the increase," Stoltenberg said. "So, we are really making progress."

WATCH: Stoltenberg on US commitment to NATO

Pence also vowed, in several meetings with European officials that the United States will "continue to hold Russia accountable," but said that Trump has directed a search for ways to find "new common ground with Russia."

Pence spoke Monday in Brussels alongside European Union Council President Donald Tusk.

“In the wake of Russian efforts to redraw international borders by force, we will continue to support efforts in Poland and the Baltic states through NATO’s enhanced forward presence initiative," Pence said.  "And with regard to Ukraine, the United States will continue to hold Russia accountable and demand that Russia honor the Minsk agreements beginning by de-escalating the violence in eastern Ukraine."

The vice president did not offer any details about potential closer ties with Russia, saying only that Trump believes they can be found.  Pence also stressed the need for cooperation to achieve free and fair economies, saying that "strengthening our economic vitality will require hard but necessary choices."

WATCH: Pence's remarks about Russia

Pence is on his first trip to Europe since taking office, intending to reassure allies the United States remains a staunch friend amid concerns about the new administration's "America First" strategy.

"Today it is my privilege on behalf of President Trump to express the strong commitment of the United States to continued cooperation and partnership with the European Union," Pence said.

"Whatever our differences, our two continents share the same heritage, the same values and above all the same purpose: to promote peace and prosperity through freedom, democracy and the rule of law," he told reporters.

Tusk said Monday's meeting was "truly needed," and that he heard from Pence words that are promising about the future and explain the Trump administration's approach.

"Too much has happened over the past month in your country and in the EU, too many new and sometimes surprising opinions have been voiced over this time about our relations and our common security for us to pretend everything is as it used to be," Tusk said.

United States Vice President Mike Pence, left, ges
United States Vice President Mike Pence, left, gestures after shaking hands with EU Council President Donald Tusk as he arrives at the European Council building in Brussels, Belgium, on Feb. 20, 2017.


Trump predicted in interviews with two European newspapers last month that other countries would follow Britain in leaving the European Union.

Tusk stressed the importance of the European Union, saying "Americans know best what great value it is to be united."

“We are counting as always in the past on the United States' wholehearted and unequivocal, let me repeat unequivocal, support for the idea of a united Europe.  The world would be a decidedly worse place if Europe were not united," Tusk said.

Pence held talks earlier Monday with EU foreign policy chief Federica Mogherini, who said on Twitter the two had an "excellent meeting, good basis for our cooperation."