There has been an increased incentive for Russia to exchange prisoners of war with Ukraine since Kyiv’s offensive in Kursk, a think tank has said.

There have been three PoW exchanges between the two countries since the Ukrainian incursion into Kursk Oblast.

The Institute for the study of war said: “Ukrainian officials have repeatedly emphasized that the Kursk incursion has enhanced Ukraine’s negotiating power in POW exchanges with Russia, following the Kremlin’s consistent rejection of Ukraine’s attempt to negotiate exchanges.

“The frequency of POW exchanges between Ukraine and Russia has significantly increased since the Ukrainian incursion into Kursk Oblast on 6 August, with both sides exchanging a total of 267 POWs each in three separate exchanges.”

Foreign Secretary David Lammy said further talks would take place involving Sir Keir Starmer, Joe Biden and the Ukrainian president at the UN General Assembly (UNGA) in New York later this month.

Asked whether the objections to making a decision were operational or political, Mr Lammy told Sky News’s Sunday Morning With Trevor Phillips programme: “I am not going to discuss the operational details of that kit. And the reason I’m not going to do that is because I’m not going to assist (Vladimir) Putin as we head into the winter.

“This is a long-standing request of Zelensky. He’s now been making it for well over a year.

“I understand why he makes that and, of course, it’s important for us to discuss the detail of that with our closest allies, and we continue to do that.

“But we head to UNGA and the UN General Assembly, where both Biden and the Prime Minister will meet Zelensky and as we head into the G7 foreign ministers (meeting) and the G20.

Five former UK defence secretaries and and Boris Johnson have urged Sir Keir Starmer to allow Ukraine to use long-range Storm Shadow missiles to strike inside Russia, even without US backing, according to The Sunday Times.

Grant Shapps, Ben Wallace, Gavin Williamson, Penny Mordaunt, Liam Fox and Boris Johnson warned the prime minister that any further delay would would only help Putin, the newspaper reported.

Former prime minister Mr Johnson told The Sunday Times: “There is no conceivable case for delay.”

“The only person who fears escalation is Vladimir Putin and every day that goes by is a lost opportunity to save lives and bring about a just conclusion to this war.”

Foreign Secretary David Lammy said the UK would not be “bullied” by Vladimir Putin’s threats of war with Nato, as international talks continued about whether Ukraine will be allowed to use western missiles to strike inside Russia.

Talks between Sir Keir Starmer and US President Joe Biden in Washington did not produce an agreement on whether the UK and US would give permission to Kyiv, but further discussions are due to take place at the United Nations later this month.

Mr Putin has warned that allowing long-range strikes “would mean that Nato countries, the United States, and European countries are at war with Russia”.

But Mr Lammy told Sky News’s Sunday Morning With Trevor Phillips programme: “Putin said ‘don’t send tanks’. We sent them.

“Putin said ‘don’t send any missiles’. We sent them.

“Putin threatens every few months to use nuclear weapons.”

Mr Lammy added: “We won’t be bullied by Putin’s shameless grandstanding.

“What he should now do is cease his aggression and leave Ukraine.”

Ukraine‘s air defence units destroyed 10 out of 14 drones that Russia launched overnight targeting its territory, Ukraine‘s air force has said.

It also said on the Telegram messaging app that Russia launched two Iskander M-ballistic missiles and one Kh-59 guided air missile targeting the southern region of Odesa.

The guided air missile was destroyed, the air force said. It did not say what happened to the Iskander missiles or whether there was any damage as a result of the attack.

Ukrainian President Volodymyr Zelenskiy said that during the past week Russia used about 30 missiles of various types, more than 800 guided aerial bombs and almost 300 attack drones against Ukraine.

The war in Ukraine has created “capability gaps” for UK forces, armed forces minister Luke Pollard has admitted – saying that giving vital equipment to troops fighting Russian invaders meant the UK now needs to “backfill” its own stocks.

The minister insisted that kit had been given to Ukrainian troops “quite correctly” by the previous Tory government, with the backing of Labour.

But he added that this support had resulted in “some capability gaps, especially in the British Army”.

He said the UK had sent “nearly all” of its AS90 mobile artillery units to Ukraine, with Mr Pollard stating: “That has created a capability gap within how we operate.”

Mr Pollard added: “That was the right decision, absolutely the right thing to do. But there is a challenge now about what do we do in the interim period.”

Mr Pollard insisted that the conflict in Ukraine “should be the wake-up call we need to make the case for a stronger defence” as he insisted the review team had not been instructed to make cuts, but would instead seek to “right-size” the UK’s military capability.