Outgoing German President Joachim Gauck and his Polish counterpart Andrzej Duda met on Monday at NATO's easternmost command center in a sign of alliance solidarity at a time of rising concern over potential Russian interference and questions over US commitments to NATO.

"This multinational corps plays an important role in assuring security at a time when politicians and societies alike have concerns as to security in Europe," Gauck said.

NATO's Multinational Corps Northeast in Szczecin, Poland, houses 400 troops from the United States and 24 other countries, including non-NATO members Sweden and Finland. In the event of Russian interference in NATO members in the Baltic states or eastern Europe, the headquarters is to lead NATO's expeditionary response.

Following Russia's annexation of Crimea in 2014, NATO sought to reassure Latvia, Estonia, Lithuania and Poland by upping policing operations in the region, conducting more joint exercises and setting up a rapid reaction force.

In July this year, NATO agreed to deploy four battalions of about 1,000 troops each to the Baltic countries and Poland. Germany will lead the battalion in Lithuania.

Gauck's visit was in part designed to send a strong signal of German support to NATO's eastern members following Donald Trump's election in the US. Over the course of the presidential campaign, Trump made several comments liable to be well received by the Kremlin, also casting doubt over the usefulness of NATO.

"It is difficult to imagine that an American president is distancing himself from the basic principles of the defense alliance," Gauck said, adding Germany's commitment to its neighbors was solid. "I assume that a principle of American foreign policy is reliability," he said, arguing thatNATO was of benefit to both the United States and Europe.

cw/msh (AP, dpa)