TALLINN, Estonia -- The U.S. committed Monday to contribute weapons, aircraft and forces, including commandos, as needed for NATO's new rapid reaction force, to help Europe defend against potential Russian aggression from the east and the Islamic State and other violent extremists from the south.

Defence Secretary Ash Carter announced the specifics of American contributions to the rapid reaction force a year after President Barack Obama made a commitment to such assistance at the NATO summit last year in Wales.

Carter said the U.S. will provide intelligence and surveillance capabilities, special operations forces, logistics, transport aircraft, and a range of weapons support that could include bombers, fighters and ship-based missiles. It would not provide a large ground force.

Carter announced the new details in Munster, Germany, after meeting with defence ministers from Germany, Norway and the Netherlands. Those countries had agreed to provide the initial troops for the rapid reaction force. The U.S. had pledged to support the task force, but NATO has been waiting to hear specifically what America was willing to provide.

The U.S., with its massive military and high-tech capabilities, has generally carried the greatest load in NATO operations, including in the Iraq and Afghanistan wars. U.S. officials made it clear early on that it would provide the enabling capabilities that other nations may not have, and not send ground forces, which other allies may be more able to do.

No final decisions have been made on the number of troops that could participate, or where they could come from. The officials said many of the forces could come from among the 65,000 U.S. military personnel already stationed in Europe.

But the plan could result in a temporary increase in U.S. forces in Europe in the event of a crisis, said U.S. officials, who spoke on condition of anonymity because they weren't authorized to discuss details of the agreement publicly.

No U.S. troops or equipment will move immediately, but instead they would be made available within 48-72 hours if requested, and approved by American leaders, in response to a crisis.

Carter said the U.S. is contributing aid "because the United States is deeply committed to the defence of Europe, as we have been for decades."

Carter also intends to talk with NATO counterparts in Estonia this week about a separate U.S. proposal to send enough tanks, Humvees and other military equipment to outfit one brigade in Eastern Europe, possibly Poland. The idea of placing such equipment in Eastern Europe as a means to reassure allies has been in discussion for months; Carter has yet to give his final approval.

Generally, a brigade has roughly 3,500 troops.

Carter's remarks in Munster came shortly after a speech in Berlin, calling for Germany and other NATO allies to stand together against Russia's aggressive behaviour and other security threats in the region.

"We do not seek a cold, let alone a hot war with Russia," Carter said at Atlantik Brucke, a Berlin think-tank that focuses on the German-U.S. relationship. "We do not seek to make Russia an enemy. But make no mistake: we will defend our allies, the rules-based international order, and the positive future it affords us. We will stand up to Russia's actions and their attempts to re-establish a Soviet-era sphere of influence."

He said that as Russia modernizes its military, it also is trying to undermine NATO and threatening to erode economic and security stability with its recent nuclear saber-rattling.

The Pentagon chief, who will attend his first NATO meeting as secretary of defence in Brussels this week, said he wants to lay out a two-pronged approach to allies, which involves bolstering Europe's military ability to deter Russia's military actions, while working with Moscow to fight terrorism and hammer out a nuclear agreement with Iran.

Carter's trip comes as the European Union extended economic sanctions against Russia until January to keep pressure on Moscow over the conflict in eastern Ukraine. And it follows Russian President Vladimir Putin's announcement that he will add more than 40 new intercontinental ballistic missiles that are capable of piercing any missile defences.