The UK is providing "self-defence" weapons and training to Ukraine amid concerns over Russia's military build-up in the region.
The Defence Secretary confirmed the first weapons systems arrived in Ukraine today, as well as the British troops training Ukrainian forces on how to use them.
Ben Wallace told MPs "in light of the increasingly threatening behaviour from Russia" and as well as our current support, the UK will supply Ukraine with light anti-armour defensive weapons systems.
"A small number of UK personnel will provide early-stage training for a short period of time, within the framework of Operation Orbital, before returning to the United Kingdom," Ben Wallce told MPs.
"This security assistance package complements the training capabilities Ukraine already has and those that are also being provided by the UK and other allies in Europe and the United States."
Mr Wallace also said "Ukraine has every right to defend its borders" and the weapons package "further enhances its ability to do so".
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"Let me be clear: this support is for short-range and clearly defensive weapon capabilities; they are not strategic weapons and pose no threat to Russia; they are to use in self-defence," he said.
Mr Wallace also told MPs the Prime Minister has been "clear" that any "destabilising action by Russia in Ukraine would be a strategic mistake" and "have significant consequences".
"That is why there is a package of international sanctions ready to go that will make sure that the Russian government is punished if it crosses the line," he said.
Mr Wallace added any invasion will be viewed as an "occupation", adding: "I fear it could lead to a huge loss of life on all sides.
"The current difficult relationship with the Kremlin is not the one we wish it to have with the United Kingdom, it does not have to be this way."
He went on to stress things in common between the two countries.
Mr Wallace earlier invited his Russian counterpart, Sergey Shoygu, to visit London "in the next few weeks".
"We're ready to discuss issues related to mutual security concerns and engage constructively in good faith," he said.
The Defence Secretary added Foreign Secretary Liz Truss "plans to visit Ukraine soon" and was "working out dates for her visit".