President Obama said Tuesday he will ask Congress for $1 billion to boost security for Poland and other nations in Europe in light of Russian aggression in Ukraine.
Security in Europe is the "cornerstone of our own security and it is sacrosanct," Obama said after landing Tuesday in Warsaw, Poland, the start of a four-day trip designed to re-assure allies.
He added that "it is a commitment that is particularly important at this point in time."
Leaders in Poland and other members of the North Atlantic Treaty Organization have expressed concern about Russia's intentions after it annexed the Crimea region of Ukraine.
The new aid, targeted mostly for NATO allies would be used for land, sea, and air military exercises and training missions throughout Europe, with an emphasis on the east.
"A persistent U.S. air, land, and sea presence in the region, especially in Central and Eastern Europe, is a necessary and appropriate show of support to allies," said a White House statement on the $1 billion proposal.
These allies contributed to counter-terrorism operations in Afghanistan and elsewhere, and "are now deeply concerned by Russia's occupation and attempted annexation of Crimea and other provocative actions in Ukraine," the statement said.
There would also be help for non-NATO nations on Russia's border, including Ukraine, Georgia and Moldova.
The White House said that "we will continue to take actions that increase the capability, readiness and responsiveness of NATO forces to address any threat."
Obama is expected to discuss the new security aid in meetings Tuesday with Polish President Bronislaw Komorowski and Prime Minister Donald Tusk.
The U.S. and Polish presidents will also meet with a group of leaders from Eastern Europe: Bulgaria, Croatia, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Romania and Slovenia.
In greeting Obama at the airport, Komorowski said the United States and Poland are a "brotherhood in arms."
Obama and Komorowski also met with U.S. and Polish F-16 pilots involved in training missions that were stepped up after Russia took Crimea.
The president is visiting Warsaw to help commemorate the 25th anniversary of free elections in Poland.
On Wednesday, Obama the incoming president of Ukraine, Petro Poroshenko.