US Vice President Joe Biden on Tuesday reaffirmed his country's commitment to NATO defence of the EU's eastern member states during high-level talks in Latvia.
"There is continued, overwhelming, bipartisan agreement in the United States of America, in both political parties, to maintain our commitment to NATO," Biden told reporters after a meeting with the leaders of the Baltic states of Latvia, Lithuania and Estonia.
"We are absolutely, thoroughly, 100-per-cent committed to our NATO obligations, including and especially Article 5," Biden said, referring to the agreement that an attack on one member is considered an attack on all members.
"The fact that you occasionally hear something from a presidential candidate of the other party, it should not be taken seriously," Biden, a Democrat, said, referring to Republican presidential candidate Donald Trump, who has questioned the alliance.
"I think he does not even understand what Article 5 is," Biden added.
Lithuanian President Dalia Grybauskaite told reporters that "it is important for us that we are ready - all parties - to confirm our strategic partnership."
"We are sure that no matter what changes will be after the election in the United States, the commitment of this country to NATO, to the Baltic region, will stay," Grybauskaite said.
The Baltic states are the geographically closest NATO members to Russia and have been fearful of a potential Russian invasion since their former Soviet ruler annexed Ukraine's southern Crimea region two years ago.
"Today our main aim for the negotiations was strengthening security and defence in the Baltic states and what would be the best way to implement the NATO summit decision made in Warsaw," Latvian President Raimonds Vejonis told reporters.
The Western military alliance decided at the summit last month to deploy NATO forces to the Baltic nations and Poland to boost security among the bloc's eastern states.
Estonian President Toomas Hendrik Ilves expressed a sentiment similar to that of his Latvian counterpart.
"I think this time it is clear that we - in Europe, the United States and North America - show that our resolve is strong and we will continue to stand for the common values that we share," Ilves said.
"We have a common resolve to stand for our values and do it wherever necessary by whatever means it takes. And for us, we have never doubted in Article 5," he added.
Biden will also visit Turkey and Sweden during his trip to Europe.