LONDON – British Defence Minister Ben Wallace is due to head to Moscow later this week as London cranks up its efforts to head off a possible invasion of Ukraine by Russian troops.

Wallace started the week meeting his Polish counterpart Mariusz Blaszczak in London on Feb. 7 to discuss the deteriorating situation and looks like ending the week in Moscow for talks with Russian defense minister Sergey Shoigu.

British Foreign Secretary Liz Truss is also due in Moscow for talks with her counterpart, Sergey Lavrov, on Feb. 10, although the visit is said to be separate to Wallace’s trip.

The British defense minister will add the Russian capital to a list of visits that has seen him shuttle between London, the Netherlands, NATO headquarters, Germany, Hungary, Croatia and Slovenia in recent weeks as tensions on the Ukrainian border rise with Moscow continuing its build-up of troops and weapons.

Wallace originally invited Shoigu to London for discussions on mutual security concerns and the rising tensions caused by the more than 100,000 Russian troops sitting on the border with Ukraine.

Instead, in reply, Shoigu invited Wallace to Moscow. For the moment nobody is confirming the precise date of the visit.

A British Ministry of Defence spokesman would only say that “later this week, the defense secretary is expected to travel to Moscow to further diplomatic discussions with his Russian counterpart.”

It’s likely to be a frosty meeting , and not because of Moscow’s chilly temperatures. Wallace has already told the British Parliament he is “not optimistic " about the outcome of the discussions.

The Moscow talks will come at the end of a hectic week for British efforts to dissuade the Russians from invading the Ukraine.

Talks with fellow NATO allies Poland coincided with an op-ed in The Times newspaper Feb. 7 by British Prime Minister Boris Johnson that outlined plans to deploy further British forces to Eastern Europe.

Wallace announced Britain is to dispatch an additional 350 troops to Poland in the coming days. Royal Marines from 45 Commando will deploy to Poland to provide support with joint exercises, contingency planning and capacity building, said the MoD in a statement.

The British said the deployment is being offered on a bilateral basis and is not part of any NATO effort.

The British already have a light cavalry squadron numbering 150 troops stationed in Poland.

In December, the U.K. deployed 140 military engineers in response to the migration crisis sparked on the border by the Belarus government. The engineers are expected to remain until April.

Britain also has around 100 troops in the Ukraine conducting training.

The British recently delivered around 2000 NLAW weapons to the Ukraine to strengthen its anti-tank capabilities.

Writing in The Times, Johnson said Britain and its NATO allies had agreed to boost troop numbers on the alliance’s eastern flank.

For Britain, the move would “reinforce the UK-led NATO battlegroup in Estonia. We would also bolster our contribution to the exercises of the Joint Expeditionary Force,” he said.

The force is a British-led formation comprising units from 10 Scandinavian and northern European countries.

Britain already has over 900 troops stationed in Estonia.

Johnson also said the government was looking to boost the defense of nations in southeastern Europe.

Deploying Royal Air Force Typhoon combat jets and Royal Navy warships to the region is under consideration, the prime minister said.

He said there could not be “a more compelling argument for the necessity of NATO than the sight of Russian tanks invading a European country once again.”

Andrew Chuter is the United Kingdom correspondent for Defense News.

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