Nato's Russia-deterrent force 'fully operational'

He said new Nato command centres in Poland and in Romania had also been “activated” and that UK jets “are currently patrolling the region’s skies” as part of a Nato brigade in Romania.

He noted that Nato will in future spend more on making sure its planes are “able to operate in heavily defended areas, meaning able to operate in areas which are covered by A2AD”.

A2AD stands for “Anti Access/Area Denial” systems, such as those installed by Russia in Kaliningrad in the Baltic Sea, in Crimea in the Black Sea and in its Mediterranean military base in Syria.

Stoltenberg also called on Moscow to use an upcoming meeting of the Nato-Russia Council, a diplomatic forum, due before the summer break, to let it know what it plans to do during its “Zapad” military drill in the Baltic region in September.

“We expect Russia to follow those obligations, they haven’t done that so far,” he said, referring to the so called Vienna Document, an international accord on military transparency.

“Russia has used different loopholes and not notified and not facilitated international inspections of their exercises for many, many years,” he said.

“We are not mirroring exactly what Russia is doing but we are responding to a more assertive Russia,” he added.

James Mattis, the US defence chief, said Nato defence ministers meeting in Brussels on Thursday had “focused on terrorism and Russia’s destabilising activities both in cyberspace and on the ground”.

Referring to the 4,500 Nato troops in the Baltic states and Poland, he said: “It is really quite energising to see young soldiers from across the Nato alliance working together in the forests of Lithuania and elsewhere”.

“When you put your troops on the ground under other nations’ command there in the forests, you are making a statement of unity,” he said.

Speaking earlier on Wednesday on a visit to Germany, Mattis also said that Russian leader Vladimir Putin was “making mischief beyond Russian borders”.

He noted that the US was planning to spend an extra $1.8 billion on its forces in Europe next year.

“Beyond any words in the newspapers, you can judge America by such actions,” he added, referring to doubts on America’s commitment to Nato joint defence that stemmed from US president Donald Trump’s flip-flopping comments on the issue.

“The US commitment to our Nato Article 5 security guarantee is ironclad,” Mattis said.

Mattis also noted that 39,000 European allies had fought with US soldiers in Afghanistan at the height of the conflict prompted by the 9/11 attack in New York.

The Nato presence in Afghanistan is now just 13,500 soldiers who are working to train native forces.

Nato ministers agreed to send more troops to the country on Thursday amid reports that Russia has begun arming the Taliban to cause problems for the US-led effort.

“Looking back on it, it’s pretty much a consensus that we may have pulled our troops out too rapidly, reduced the numbers a little too rapidly,” Mattis said.