The US Air Force has deployed two nuclear-capable B-2 stealth bombers to a British air base for exercises with NATO allies, the Pentagon said Monday.

The deployment, which the Pentagon said was pre-planned and short-term, comes against a backdrop of tension with Russia over unrest in Ukraine.

"It certainly is yet another demonstration of America's ironclad commitment to the NATO alliance," said Colonel Steve Warren, a Pentagon spokesman.

US military deployments have increased in recent weeks as Washington seeks to reassure Eastern European allies worried about Moscow's moves in the region.

The two B-2 bombers arrived Sunday at RAF Fairford in Gloucestershire, England, where they joined three other B-52 strategic bombers that got there on June 4.

"These multi-role heavy bombers will conduct training flights in the US Eucom area of operation, providing opportunities for the air crews to sharpen their skills and increase interoperability," Warren said.

Overseas deployments of the B-2 are rare, as the United States jealously guards the costly aircraft's secrets. There are only 20 B-2s in existence.

A B-2 bomber overflew South Korea last year during an exercise amid tensions with the North.

Based at Whiteman Air Force Base in Missouri, the B-2 were designed to penetrate the world's most formidable air defenses and drop dozens of precision, conventional or nuclear bombs.

Lavrov slams EU Russia policies, NATO expansion
Turku, Finland (AFP) June 09, 2014 - Russia on Monday accused the European Union of putting pressure on Bulgaria to suspend work on a key Kremlin-backed gas pipeline, and said eastward expansion by NATO was "counterproductive".

Foreign Minister Sergei Lavrov said EU member state Bulgaria's move to halt work on the South Stream gas pipeline suggested the bloc was seeking revenge over the Ukraine crisis.

"It's unclear what they want from us. In my opinion, on Ukraine we are already doing everything that is necessary to calm down the situation," Lavrov said after talks with his Finnish counterpart Erkki Tuomioja in Turku.

"Sometimes Brussels is guided by a desire to punish, a desire to take revenge," Lavrov said.

"As far as EU policies over Russia are concerned I don't think one can find any serious politicians who would call them constructive."

Lavrov also criticised NATO's decision last week to beef up security in eastern Europe.

"An artificial attempt to continue NATO expansion to the east and any other direction, to continue moving military infrastructure closer towards the borders, including Russia's borders, is definitely counterproductive and contradicts the obligations which NATO country members have taken upon themselves," he said.

Russia's top diplomat said the EU should stop pressing Ukraine to choose between Russia and the West, saying all three parties should find a way to cooperate in a three-way format.

"We still believe it would be the ideal way forward," Lavrov said.