U.S. President Barack Obama says he believes democracy and the rule of law will triumph in Ukraine.
Mr. Obama spoke late Wednesday to an enthusiastic audience at Brussels' Palais des Beaux Arts, after meetings with European Union and NATO officials.
He said Western powers do not have any plans to try to dislodge Russia from Crimea by force. But he said over time, if the West remains united, Russia will recognize that it cannot use brute force to achieve its goals.
Earlier Wednesday, Mr. Obama said after meeting with EU leaders that the international community is united in its determination to isolate Russia because of its annexation of Crimea, and that the issue highlights the need for Europe to find other sources for its energy supplies.
He said Russia's energy sector could be the next target of economic sanctions by the United States and the European Union.
Mr. Obama told reporters in Brussels that NATO needs a regular presence in countries that feel vulnerable to Russia. He said the situation in Ukraine is a reminder that "freedom isn't free" and added that collective defense means "everybody's got to chip in" to maintain a deterrent force.
U.S. Secretary of Defense Chuck Hagel said Wednesday that Russia has continued to build up military forces along its border with Ukraine, despite assurances it has no intention to invade.
Meanwhile, the World Bank said in a report published Wednesday that if Moscow's standoff with the West over Crimea intensifies, the Russian economy could contract 1.8 percent in 2014 and investors could pull a record $150 billion out of the country.
President Vladimir Putin's popularity rating has soared with Crimea's annexation: a poll published Wednesday by the Levada Center, an independent Russian polling agency, found that public support for Mr. Putin had risen to 80 percent during the past week.
However, Boris Nemtsov, a former Russian deputy prime minister who is now a democratic opposition leader, told VOA's Russian service that Mr. Putin's popularity could drop as Russians start to feel the costs of the move into Crimea.
"When citizens realize they have to pay for this adventure out of their own pockets, they will start to sober up," Nemtsov said.
On Monday, President Obama and leaders from Britain, Canada, France, Germany, Italy and Japan said they were suspending their participation with Russia in the G8 until Moscow "changes course."
But Russian news agencies quoted a Kremlin spokesman as saying Russia is ready for and interested in continuing contacts with its fellow G8 countries.
The current instability surrounding Ukraine began last November, when then-President Viktor Yanukovych backed off from signing a trade agreement with the European Union in favor of closer ties with Russia. The move led to weeks of anti-government protests in Kyiv that forced the pro-Russian Mr. Yanukovych to flee the country last month.
People in Crimea voted last week in a highly controversial ballot to secede from Ukraine and join the Russian Federation, a move quickly embraced by Russia's President Putin. The United States and the European Union say the vote violates Ukraine's constitution and is illegal.
Russia, meanwhile, is showing no signs of pulling its forces from Crimea, and Ukrainian troops have withdrawn from installations there. On Tuesday, Ukrainian marines began leaving Crimea by the busload as Russian forces took control of the last remaining military base under Ukrainian control.
President Obama says Washington is still concerned about "further encroachment" into Ukraine by Russia.