Her speech will be delivered a day after a series of international events to mark the third anniversary of Russia’s invasion of Ukraine.

Discussions around peace talks have rapidly evolved over the past week after US President Donald Trump opened negotiations with Russia, in a meeting which excluded Ukraine.

President Trump has said he wants a quick end to the war and has claimed Russian President Vladimir Putin also wants to reach a deal.

Meanwhile, there has been a deepening rift between Trump and Ukrainian President Zelensky.

Zelensky has accused the US president of helping Russia “break out of years of isolation” before Trump turned his ire on the Ukrainian leader, calling him a “dictator” and suggesting his country started the war.

On Thursday, Sir Keir will visit the White House to make the case for Ukraine’s direct involvement in any peace talks, warning that an insecure settlement without security guarantees for Kyiv could embolden Russia to attack again.

The prime minister also signalled a shift in the government’s approach to bringing about peace, including stepping up UK military support and taking a bigger role in Europe’s security.

Trump has been putting pressure on European Nato allies to increase their defence spending.

In her speech, Badenoch will also advocate for further investment in defence and argue the government “must do what it takes to protect Britain”.

The Conservatives ran on a manifesto pledge to increase defence spending from 2.3% to 2.5% of GDP by 2030, but in recent days have pressed Labour to go further.

“There will be painful decisions on government spending,” Badenoch will say.

“Any country that spends more interest on its debt than on defence, as the UK does today, is destined for weakness.”