The UK has sold 123 armoured vehicles to Nato member Latvia to help boost the Russian neighbour's military capabilities.
The Ministry of Defence (MoD) announced the £40m sale as world leaders gathered in Newport, South Wales, for the 2014 Nato Summit and it comes in the wake of Vladimir Putin's annexation of Crimea and the deployment of Russian troops in Ukraine.
The vehicles, which have been involved in operations in Bosnia and Herzegovina, Iraq and Afghanistan, had been considered surplus by the MoD in the 2010 Spending Review but have been overhaul in time to hand them over to the Latvians.
Speaking at the Nato Summit, Defence Secretary Michael Fallon said: "I am delighted that Latvia will soon benefit from these proven and life-saving battlefield capabilities, including ambulances and command centres.
"This is just one way we are supporting our Baltic Nato allies. As a leading member of Nato, the UK is keen to restate publicly our support for the collective security of its members and enable our partners to contribute to international peacekeeping and security operations."
The deal will likely raise eyebrows in the Kremlin, which has previously been suspicious of Western involvement in border nations including Poland, Georgia and the Czech Republic.
Further ire could also be sparked in Moscow if Ukraine follows in the footsteps of Georgia and is successful in its bid for accession to Nato.
On 3 September, Ukrainian Prime Minister Arseniy Yatseniuk reaffrimed his nation's intention to join the alliance. He said: "Concerning Nato, I consider the most correct decision would be one to accept Ukraine as a member of Nato."
'Russia has ripped up the rulebook'
Meanwhile, David Cameron and Barack Obama have used a joint article in The Times newspaper to condemn Russian hostilities on its borders and spell out their commitment to Nato members.
"To the east, Russia has ripped up the rulebook with its illegal, self-declared annexation of Crimea and its troops on Ukrainian soil threatening and undermining a sovereign nation state," the leaders wrote.
"With Russia trying to force a sovereign state to abandon its right to democracy and determining the course of its future at the barrel of a gun, we should support Ukraine's right to determine its own democratic future...[and keep] reassuring Nato members in Eastern Europe and making clear to Russia that we will always uphold our Article 5 commitments to collective self-defence."