NATO's commander announced limited and temporary steps Wednesday to bolster alliance defenses against Russia as Ukraine struggled to regain control of separatist eastern cities.

The announcement by Air Force Gen. Philip Breedlove came as Ukrainian forces failed to push pro-Russian militants out of eastern Ukraine.

Near the eastern town of Slavyansk, Ukrainian troops surrendered several armored personnel carriers to armed groups who triumphantly rode them back into town, according to Western media reports.

Following a meeting in Brussels, the North Atlantic Council, NATO's governing body, approved Breedlove's recommendations to boost air patrols over the Baltic states and post more ships to the Mediterranean.

Breedlove later told reporters that the measures were temporary and were "planned to be sustainable as a minimum through 31 December. NATO will review this later in the year to decide which measures should go beyond that date," he said.

Breedlove said the limited measures were needed to counter Russia's aggressive stance.

"We've had a paradigm shift, change, gone through a period where I think we thought we were past the time when military force would be used to change international borders in Europe," Breedlove said of Russia's annexation of Crimea.

Breedlove said he planned to brief Gen. Valery Gerasimov, chief of staff of the Russian military, on the NATO actions to "avoid military misinterpretation."

The announcements in Brussels came ahead of Defense Secretary Chuck Hagel's meeting at the Pentagon Thursday with Polish Defense Minister Tomasz Siemoniak on additional measures to counter Russia.

Earlier, NATO Secretary General Anders Fogh Rasmussen said NATO "will have more planes in the air, more ships on the water, and more readiness on the land" based on Breedlove's recommendations.

Rasmussen said NATO would conduct more air policing missions over the Baltic states, and send more ships to the Baltic Sea and the Mediterranean. He made no mention of the Black Sea, where the U.S. Aegis missile destroyer Donald Cook is currently on deployment.

The Cook was expected to conduct exercises later this week with the Romanian navy following a faceoff with a Russian Su-24 Fencer fighter that made multiple low passes near the destroyer last Saturday.

Rasmussen also made no mention of a possible deployment by the Fort Hood-based 1st Brigade, 1st Cavalry Division. The 1st Brigade has been designated as the U.S. unit in the NATO Reaction Force.

The increased NATO presence around the Baltics will be felt in a matter of days, Rasmussen said.

"More (measures) will follow, if needed, in the weeks and months to come," but he stressed that the measures were aimed at de-escalating the crisis ahead of the meeting in Geneva Thursday between the U.S., Russia, Ukraine and the European Union.

Russian Foreign Minister Sergei Lavrov and Ukraine's acting Foreign Minister Andriy Deshchytsia will be joined by Secretary of State John Kerry and European Union foreign policy chief Catherine Ashton.

In Kiev, Prime Minister Arseniy Yatsenyuk accused Russia of orchestrating the unrest in the eastern region that has seen militants take over government buildings in several cities.

"Russia has got a new export now, apart from oil and gas -- Russia is now exporting terrorism to Ukraine," Yatsenyuk told a Cabinet meeting. "Russia must withdraw its sabotage groups, condemn terrorists and liberate all administrative buildings."

-- Richard Sisk can be reached at richard.sisk@monster.com