U.S. President Barack Obama had reassuring words about the European Union in the wake of Britain's "Brexit" vote to leave the bloc.
"We cannot lose sight of the extraordinary achievement that European integration continues to be," he said in Warsaw, flanked by European Council President Donald Tusk and European Commission President Jean-Claude Juncker.
"More than 500 million people speaking 24 different official languages in more than two dozen countries, 19 with a current currency," he said. "Every member of the EU is a democracy. No EU country has ever raised arms against another."
Despite the challenges, Obama said the United States will always have "a strong and enduring interest in a united, democratic Europe."
Kremlin spokesman Dmitry Peskov has blasted NATO as an "absolutely short-sighted organization" for suggesting Moscow poses a threat to Europe.
"It is absurd to talk about any threat coming from Russia at a time when dozens of people are dying in the center of Europe and when hundreds of people are dying in the Middle East daily," he said.
"We aren't the ones getting closer to NATO's borders," he added.
U.S. President Barack Obama pledged support for Ukraine and for continued sanctions on Russia.
"We'll continue to support Ukraine as it continues to undertake important political and economic reforms," he said in Warsaw. "The EU and the US are united in our commitment to maintaining sanctions on Russia until they fully implement its obligations under the Minks agreement."
New NATO-EU declaration calls for the use of "all ways and means available" to address "challenges emanating from the south and East."
