NATO allies including the U.S., Britain and Canada pledged Wednesday to deploy forces, tanks, jets and artillery in Eastern Europe amid escalating tensions with Russia.

Following a NATO defense ministers meeting in Brussels, Britain announced it would send fighter jets to Romania in 2017, while the U.S. promised tanks, artillery and more than 900 troops to Poland, Reuters reports. The U.K., Germany, Canada and other allies had also committed to contribute to a 4,000-strong ground force in the Baltic states and Eastern Europe, which aims to check Russian belligerence in the region.

Speaking at a press conference, NATO Secretary-General Jens Stoltenberg said the reinforcement would be the biggest build up of NATO forces since the end of the Cold War.

NATO accuses Moscow of continuing to support pro-Russian rebels in Ukraine following the annexation of the Crimean peninsula in 2014, and the alliance believes Russia has stationed around 330,000 troops close to its western border.

Stoltenberg said the build up of troops was a measured response to Moscow’s actions. “This month alone, Russia has deployed nuclear-capable Iskander missiles to Kaliningrad and suspended a weapons-grade plutonium agreement with the United States,” he said according to Reuters.

The announcement came as Russian warships sailing through the English Channel, believed to be on their way to Syria, withdrew a request to stop to refuel in Spain amid international opposition, the BBC reports.

At a July summit in Warsaw, NATO said it expected to deploy four battalions by early 2017. “I am pleased to confirm that we are on track. This Alliance does what it says. And we deliver on our promises,” Stoltenberg told reporters.

A 40,000-strong rapid-reaction force would support the four battalions, with follow-on forces on hand if necessary.

[Reuters]

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