(Adds quotes, detail, background)
By Roberta Rampton
VILNIUS, March 19 (Reuters) - U.S. Vice President Joe Biden reassured the leaders of Lithuania and Latvia that the United States would defend any NATO members against aggression and warned that Russia was on a "dark path" to isolation over its actions in Ukraine.
Biden was in the capital of Lithuania, part of a quick trip to reassure Baltic allies worried about what an emboldened, aggressive Russia might mean for their nations. Lithuania, along with Estonia and Latvia, are NATO members.
"We stand resolutely with our Baltic allies in support of the Ukrainian people and against Russian aggression," Biden told reporters.
"As long as Russia continues on this dark path, they will face increasing political and economic isolation," Biden added, referring to reports of armed attacks against Ukrainian military personnel in Crimea.
The Baltic nations have condemned Russian President Vladimir Putin for moving to annex Ukraine's Crimea, and the White House has said it is preparing a fresh round of sanctions in response.
Biden's visit, which included a trip to Warsaw on Tuesday, is intended to reassure nations like Poland and the Baltics that the United States will live up to its NATO pledge to protect allies under attack. Estonia, Latvia, Lithuania and Poland are all members of both the European Union and NATO - unlike Ukraine.
Biden told Estonian President Toomas Hendrik Ilves earlier this week that the United States may rotate U.S. forces into the region to conduct ground and naval exercises and training missions. Washington also has added more fighter jets to help patrol airspace over the Baltics.
On Wednesday, Biden held talks with Lithuanian President Dalia Grybauskaite and Latvian President Andris Berzins at Lithuania's presidential palace.
"We see that there is an attempt, using brutal force, to redraw borders of the European states and to destroy the post-war architecture of Europe," Grybauskaite said.
The Baltics are worried not just about Russia's intentions but also about the economic impact of rising tensions if Russia retaliates through trade bans or by withholding natural gas.
Last week, Russia suspended food imports through Lithuania's major port, Klaipeda, a move local businesses saw as Moscow's way of exerting political pressure.
Latvia's finance minister said on Monday that the EU should compensate any countries hurt by its sanctions against Russia. (Reporting by Roberta Rampton and Andrius Sytas; Additional reporting by Niklas Pollard in Stockholm; Editing by Alistair Scrutton)
Our Standards: The Thomson Reuters Trust Principles.