President Bush says when Europe and America are united, "no problem and no enemy can stand against us."
In his weekly radio address, Bush said NATO must show resolve and foresight to "be prepared to meet the challenges of our time."
He cited NATO's role in Afghanistan and in supporting Polish peacekeepers in Iraq.
Bush singled out Poland, calling it a proud member of NATO and a country that has seen "both the horror of tyranny and the hope of liberty."
Poland was a staunch supporter of the Iraq war. It sent 200 troops to fight in the war and has pledged two-thousand peacekeepers.
Bush signaled his appreciation by making Poland his first stop on a seven-day trip to Europe and the Middle East.