The meeting between US President Donald Trump and Russian President Vladimir Putin “could be the first step” towards peace in the Ukraine conflict, Defence Secretary John Healey has said.
He added that the UK were ready to “put boots on the ground” in Ukraine to reinforce a ceasefire, in the event that one is agreed.
However, he also said the government was prepared to “step up economic sanctions and pressure on Putin if he shows today in Alaska he really isn’t serious”.
Trump has described the summit, which is due to start at 20:00 BST, as a “feel-out meeting” and said his goal is to “set the table” for a meeting between Zelensky and Putin.
Zelensky has warned that Putin is “bluffing” but Trump said he believed the Russia president was “not going to mess around with me”.
He added there was 25% chance that the meeting would “not be successful”.
Trump is hoping he can end the war, which started when Russia invaded Ukraine in 2022, costing huge loss of life on both sides.
The US president has said any resolution would have to involved a “give and take” of boundaries between the two countries.
Ukraine has insisted that ceding territory would be unacceptable, while Russia wants to maintain control of land it has seized, including Crimea, and also wants assurances that Ukraine will not join the Nato military alliance.
Like Zelensky, European leaders have not been invited to the meeting in Alaska, but sought to influence the US president in a joint phone call on Wednesday.
Asked on Breakfast if the UK’s role was to “watch and wait”, Healey said: “No, the UK’s role is to stand with Ukraine on the battlefield and in the negotiations, and prepare as we have been, leading 30 other nations with military planning for a ceasefire and a secure peace through what we call the coalition of the willing.”
The coalition of the willing is a group of around 30 mainly European countries who have pledged to defend a peace deal in Ukraine.
Healey said more than 200 military planners from the coalition had been working over the last few months “doing detailed planning for the point of a ceasefire”.
He said multi-national forces were “ready to act from day one” adding: “The military plans are complete.”
“We are ready to put UK boots on the ground in Ukraine in part to reassure Ukrainians.
“But also in part to secure the safe skies, safe seas and to build the strength of the Ukrainian forces, because in the end the best deterrence against Russia… re-launching their aggression against Ukraine is the strength of Ukraine to stand for itself.”
Asked what would happen if Russia attacked British troops when they were in Ukraine, Healey said he would not discuss hypotheticals.
However, he added that there were “important principles” and that British forces would have “the right to defend themselves if attacked”.
Zelensky visited the UK Prime Minister Sir Keir Starmer on Thursday. Following the meeting, Zelensky said the pair had discussed weapons partnerships including investment in drone production and the One Hundred Year Partnership, due to be ratified this month.