About 200 paratroopers from the U.S. Army's 173rd Airborne Brigade will join allied military exercises in Ukraine next week despite Moscow's warnings against a NATO presence during the ongoing crisis in eastern Ukraine, the Pentagon said Wednesday.

The "Sky Soldiers" of the 173rd, based in Vicenza, Italy, will focus on patrolling, de-mining and convoy clearance training from Sept. 15-26 with Ukrainian troops and units from 14 other nations in the annual Rapid Trident exercise, said U.S. Army Col. Steve Warren.

The exercise will involve approximately 1,300 personnel from nations including Azerbaijan, Bulgaria, Canada, Georgia, Germany, Britain, Latvia, Lithuania, Moldova, Norway, Poland, Romania, and Spain.

In addition, the U.S. guided-missile destroyer Ross will participate with Ukrainian ships in Sea Breeze naval exercises in the Black Sea from Sept. 8-10, Warren said.

In another sign of increasing NATO activity in Eastern Europe, six U.S. F-16 fighters from the 31st Fighter Wing based in Aviano, Italy, and 120 support personnel were headed to the Lask air base in Poland, Warren said. From Lask, the F-16s will participate in the joint terminal attack air defense exercise in the Czech Republic from Sept. 4-8.

Russia denounced the exercises in Ukraine and increased NATO activity as an "external threat" and warned against Ukraine joining NATO.

"The fact that the military infrastructure of NATO member states is getting closer to our borders, including via enlargement, will preserve its place as one of the external threats for the Russian Federation," Mikhail Popov, deputy director of Russia's national security council, told the RIA Novosti news agency.

The troop movements were announced on the eve of the NATO ministerial meeting in Wales and amid conflicting reports of a ceasefire in Ukraine.

President Obama, who will attend the summit, told students in Tallinn, Estonia, on Wednesday that Russia had committed "a brazen assault on the territorial integrity of Ukraine, a sovereign and independent European nation."

Obama called on the allies to provide more military assistance to Ukraine, but stopped short of saying that the U.S. would go beyond providing Ukraine with Meals Ready to Eat and other non-lethal aid.

"Now, Ukraine needs more than words," Obama said. "NATO needs to make concrete commitments to help Ukraine modernize and strengthen its security forces."

In remarks to the Naval War College in Rhode Island, Defense Secretary Chuck Hagel said that Russian President Vladimir Putin bore sole responsibility for the Ukraine crisis. 

"It's one individual -- it's the Russian president who continues to take very dangerous escalatory action," Hagel said.

The U.S. defense secretary followed the course of other Obama administration officials in declining to call Russia's actions in Ukraine an "invasion" but said "there are Russians in Ukraine.

"You can define it any way you will," he said.

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