Britain will provide Ukraine with “light armour defensive” weapons and training as Western powers fear an “increasingly threatening” Russia will invade the country.
Defence Secretary Ben Wallace said the weapons being supplied are “short range” and to use in “self-defence”, adding that they are not “strategic” and “pose no threat to Russia”.
Mr Wallace added that a “small number” of UK personnel will travel to Ukraine to provide training.
However, he said the UK will not offer the “false hope” of sending troops to the eastern European country if war does break out.
Mr Wallace said in the House of Commons: “I have to be honest here, Russia has the biggest armed forces in Europe.
“Ukraine is not a member of NATO and I think it would be false hope to say that the British armed forces would be going unilaterally to Ukraine to join forces alongside Ukrainians in that environment, which is why we are putting all the effort in helping Ukraine help themselves, sanctions packages and diplomatic efforts.”
Mr Wallace made the announcement as he warned tens of thousands of Russian troops are positioned next to the Ukrainian border.
He added that the deployment is “not routine” and they are equipped with tanks, armoured fighting vehicles, rocket artillery and short-range ballistic missiles.
He told MPs there is “real cause of concern” over the scale of the force being assembled by the Kremlin, supported by Russian air and maritime forces.
Russia’s presence and levels of readiness are contributing to a “destabilising and coercive atmosphere that risks miscalculation at best and at worst conflict”, Mr Wallace added.
He invited his Russian counterpart, Sergey Shoygu, to visit London “in the next few weeks” to discuss “issues related to mutual security concerns and engage constructively in good faith”.
After highlighting previous work as part of Operation Orbital, the UK’s training mission in Ukraine, Mr Wallace outlined new support being provided.
He told the Commons: “In light of the increasingly threatening behaviour from Russia and in addition to our current support, the UK is providing a new security assistance package to increase Ukraine’s defensive capabilities.
“We have taken the decision to 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.
“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.
“Ukraine has every right to defend its borders and this new package of aid further enhances its ability to do so.
“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.”
Mr Wallace reiterated there is a “package of international sanctions ready to go” should any “destabilising action” by Russia take place in Ukraine.
He noted 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.”
Mr Wallace said when it comes to the UK’s relationship with Russia, “the current gap is wide but it is not unbridgeable”.
Mr Wallace added: “We wish to be friends with the Russian people as we have been for hundreds of years. And there is a world in which we can establish a mutually beneficial relationship with Russia.
“I still remain hopeful that diplomacy will prevail. It is President Putin’s choice whether to choose diplomacy and dialogue, or conflict and the consequences.”
Mr Wallace said Foreign Secretary Liz Truss “plans to visit Ukraine soon” and was “working out dates for her visit”.