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U.S. President Barack Obama called NATO the "cornerstone for global security" after meeting with NATO Secretary-General Jens Stoltenberg in the Oval Office of the White House on Tuesday, during which the President said the two discussed the situation in Ukraine and the "increasingly aggressive posture that Russia has taken."
He said he was pleased to hear from Stoltenberg that U.S. and allies are doing what's necessary to put resources in place to protect NATO members.
Stoltenberg said the two also discussed the importance of the Minsk agreement, a truce agreed to in February between leaders from Ukraine and Russia - even though clashes have continued in the region.