NATO allies have already rushed to strengthen the alliance's eastern flank with thousands of troops and hardware as fears have soared that Moscow could be about to invade its pro-Western neighbour Ukraine.

US and allies plan to weigh the possibility of stationing troops longer-term in southeast Europe, possibly starting later this year.
US and allies plan to weigh the possibility of stationing troops longer-term in southeast Europe, possibly starting later this year. (AP)

NATO chief Jens Stoltenberg has said the alliance is looking to step up efforts to strengthen its eastern flank, as he has warned the threat from Russia has become the "new normal in Europe".

"Today, ministers decided to develop options to further strengthen NATO's deterrence and defence, including to consider establishing new NATO battle groups in central and southeastern Europe," Stoltenberg on Wednesday said after a meeting of the alliance's defence ministers.

He said the ministers agreed for military commanders to come up with new options for strengthening NATO's defences in southeast Europe near Romania.

“Moscow has made it clear that it is prepared to contest the fundamental principles that have underpinned our security for decades, and to do so by using force. I regret to say that this is the new normal in Europe,” Stoltenberg said.

Over two days at NATO headquarters in Brussels, defence ministers were to discuss how and when to rapidly dispatch troops and equipment to countries closest to Russia and the Black Sea region should Moscow order an invasion of Ukraine.

READ MORE: NATO sees ‘no sign of de-escalation’ as Russia pulls back some troops

'No room for any miscalculation'

“The fact that we have deployed more NATO troops on the ground, more naval assets, more aircraft, all of that sends a very clear message,” Stoltenberg said.

“I think there is no room for any miscalculation in Moscow about our commitment to defending allies.”

Over the last four months, Russia is estimated to have amassed around 60 percent of its entire land forces and a significant portion of its air force to the north and east of Ukraine, as well as in neighboring Belarus. 

Moscow has appeared ready to repeat its 2014 invasion of Ukraine, but on a grander scale.

However, over the last two days, Russia has said that it was returning some troops and weapons to bases, but Stoltenberg said the allies saw no concrete sign of a drawdown and that concern that Russia might invade Ukraine persists.

“They have always moved forces back and forth, so just that we see movement of forces, that doesn’t confirm a real withdrawal," Stoltenberg said. 

“The trend of the last weeks and months has been a steady increase in the Russian capabilities close to Ukraine’s borders."

READ MORE: Can Germany and France ease tensions in the Ukrainian crisis?

Source: TRTWorld and agencies