Defence Secretary John Healey has insisted European leaders “must do everything we can to step up our support for Ukraine” ahead of a crunch defence summit.

Mr Healey said Kyiv’s troops are “fighting for the same values and same beliefs and same freedoms that we prize”.

Thousands of UK troops will be put on stand-by to deploy to Estonia’s border with Russia under a new agreement Britain has signed with the Baltic nation in another sign of the commitment to European defence, Mr Healey said at a meeting of Nato counterparts.

The Cabinet minister’s message came as the UK pushes for a closer relationship with the European Union, particularly on security matters.

It could also be a sign of European efforts to do more on the defence of the continent with an eye on November’s US election, which could see Donald Trump – who has been critical of NATO – return to the White House.

Arriving at Nato headquarters in Brussels, Mr Healey said: “Today, we will make the commitment to reinforce NATO’s eastern flank with a new plan alongside Estonia for our forces there.

“And we will make a commitment, a UK commitment, to bolstering the future of Europe’s defences, leading a new initiative to net together the European air defence systems and to work together with other European allies to develop long-range missiles.

“This is part of the UK’s new determination to work more closely with other European allies on security for the future, and Europe’s security is guaranteed by this Nato alliance.”

Ukrainian President Volodymyr Zelensky was also attending the Nato defence ministers’ meeting in Brussels to outline his “victory plan” for the war against Russia.

Mr Healey said: “We, as Ukraine‘s supporters, must do everything we can to step up our support for Ukraine in the weeks and months ahead, to put more pressure on Russia, to ensure that Ukraine can prevail, because the defence of Europe starts in Ukraine.

“They’re fighting for the same values and same beliefs and same freedoms that we prize and we owe them that duty to stand with them for as long as it takes.”

Under the plans announced by the Ministry of Defence, soldiers in the Army’s 4th Brigade will be held at “high readiness” in order to defend Nato’s eastern flank with Russia

The Defence Secretary will also agree plans to lead the new Diamond (Delivering Integrated Air and Missile Operational Networked Defences) initiative, aimed at integrating Nato member states’ missiles defences, while also developing new long-range weapons.

Some 1,000 British troops are already stationed in Estonia. If deployed, 4th Brigade troops – who are specialists in operating in Estonia’s Baltic terrain – could be sent there along with helicopters and rocket launchers.

The 4th Brigade, based at Bourlon Barracks in North Yorkshire, would be deployed within 10 days if called up to travel to Estonia under the plans.

The Army’s most advance tank, the Challenger 3, as well as the Boxer armoured vehicle, could also be sent to Estonia in future.

Army brigades differ in size, but as many as 5,000 troops could be placed on stand-by under the pact, which will begin in July 2025.