The West must give Ukrainian armed forces the “advanced, Nato-standard capabilities” needed to banish Russian troops from its land, the Prime Minister is due to say.

Rishi Sunak will tell the Munich Security Conference that more needs to be done to “boost Ukraine’s long-term security” and that leaders must “double down” on military support for the war-torn country.

The Prime Minister will use his afternoon speech at the German global security forum on Saturday to argue that securing a lasting peace for Ukraine will require international law to be strengthened.

With the one-year anniversary of the bloody conflict approaching, he will also press for a new plan to protect Ukraine’s sovereignty in the future against Russian aggression, saying that Kyiv’s struggle is “about the security and sovereignty of every nation”.

The intervention follows Ukrainian president Volodymyr Zelensky’s visit to Britain, Paris and Brussels last week as he made the case for the West to send fighter planes for his air force.

Mr Sunak used Mr Zelensky’s surprise visit to announce a two-pronged approach to support for Ukraine, offering military kit immediately to fend off a Russian spring offensive while also preparing its forces for the longer term.

To coincide with the war leader’s momentous trip, the UK Government announced that Britain would extend its training mission – which has already seen 10,000 Ukrainian troops come to the UK – to cover fighter jet pilots, ensuring Ukraine can defend its skies using “Nato tactics” in the future.

The training of pilots is expected to commence in the spring, according to Downing Street officials.

The Prime Minister’s visit to Germany comes as some in Ukraine suggest a spring-time offensive by Russian president Vladimir Putin’s forces has already begun along parts of the eastern frontline.

Mr Sunak is expected to tell the forum that the West, in the face of ramped-up Russian attacks, must continue to back Kyiv.

“Now is the moment to double down on our military support,” he is due to say.

“When Putin started this war, he gambled that our resolve would falter. Even now he is betting we will lose our nerve.

“But we proved him wrong then, and we will prove him wrong now.”

In an apparent attempt to encourage others in the West to offer long-term training to Kyiv’s armed forces, the Conservative Party leader will warn leaders that Ukrainians are fighting for the security of all nations.

“We need to do more to boost Ukraine’s long-term security,” Mr Sunak is scheduled to say in his speech.

“We must give them the advanced, Nato-standard capabilities that they need for the future.

“And we must demonstrate that we’ll remain by their side, willing and able to help them defend their country again and again.

“What is at stake in this war is even greater than the security and sovereignty of one nation.

“It’s about the security and sovereignty of every nation.

“Because Russia’s invasion, its abhorrent war crimes and irresponsible nuclear rhetoric are symptomatic of a broader threat to everything we believe in.”

In the last year, No 10 officials said £2.3 billion of UK military support to Ukraine has provided a squadron of Challenger 2 tanks, 200 other armoured vehicles and more than 10,000 anti-tank missiles and multiple-launch rocket systems.

The Prime Minister has said he is committed to matching or exceeding that level of support this year.

Sir Keir Starmer, who has been visiting Ukraine in recent days, said a Labour administration would maintain the defence, training and technological support the Government is providing.

“Throughout this conflict, I’ve made clear that there will be no difference between the UK political parties on this,” the Labour leader said.

“We will continue to work with the Government to see what further support we can provide, but any support must be provided in lockstep with Nato powers.”

Sir Keir added that “there must also be justice, and reparations for the rebuilding of Ukraine”.

Reports suggest Mr Sunak will also use his Munich trip to hold talks on the fringes of the summit with European leaders about a deal to fix issues with the Northern Ireland Protocol, part of Britain’s Brexit agreement with the European Union.