David Lammy said he has seen “no sign” that Russian president Vladimir Putin is serious about a peace deal with Ukraine.
The Foreign Secretary urged Mr Putin to agree to a “full and unconditional ceasefire now” before warning Britain and its allies have “more cards that we can play” to help force Russia to negotiate “seriously”.
This includes action to further squeeze Russia’s oil revenues and make use of frozen assets, according to Mr Lammy.
His remarks came in a statement to the House of Commons following the latest meeting of the G7 countries, which also include Canada, France, Germany, Italy, Japan and the United States.
After Mr Lammy said the G7 countries are “united” in supporting Ukraine and its pursuit of peace, he told MPs: “Now it is Putin who stands in the spotlight, Putin who must answer, Putin who must choose – are you serious, Mr Putin about peace?
“Will you stop the fighting or will you drag your feet and play games, pay lip service to the ceasefire whilst still pummelling Ukraine?
“My warning to Mr Putin is this: if you are serious, prove it with a full and unconditional ceasefire now.
“And if Putin does not deliver, and I must tell the House that I currently see no sign yet that he is, the G7 meeting helped us ready the tools to get Russia to negotiate seriously.
“We’re not waiting for the Kremlin.
“If they reject a ceasefire, we have more cards that we can play.
“We can all see the impact the G7’s unprecedented sanctions have had on Russia’s faltering economy; social spending down, inflation and interest rates sky high.
St Basil’s Cathedral, in Moscow’s Red Square (Ian Nicholson/PA)
“There can be no let up in our efforts.
“In Canada we discussed where we can go further to target their energy and defence sectors, further squeeze their oil revenues and use frozen Russian assets.
“At the same time we will keep up our support to Ukraine, Europeans clearly need to shoulder our share of this responsibility.
“We in the UK are stepping up on drones, on munitions and on training.”
Mr Lammy highlighted the Government’s commitment to increase defence spending before adding: “We’re urging our allies to do the same so that Ukraine is in the strongest possible position now and in any peace that follows.”
He said there needs to be “a new era in UK-EU security cooperation” and he will host the European Commission’s Kaja Kallas on Tuesday.
Mr Lammy went on: “We’re taking steps to ensure Russia does not come back for more.
“We know the history – Budapest, Minsk, paper promises betrayed by Putin.
“Together with France we’re establishing a coalition willing to deter Russia from invading again.
“To be credible, it will need US support.
“But Britain and our allies recognise that we need to step up and this Government is leading the effort on multiple fronts.”