Foreign Secretary Dominic Raab has said the number of UK nationals left behind in Afghanistan is in the “low hundreds” after the western military presence came to an end in the country.

The Cabinet minister said on Tuesday he was unable to give a “definitive” figure on how many Afghans the UK had failed to airlift to safety after the Taliban seized power.

Mr Raab was also forced to deny a Pentagon leak suggesting the US wanted to close a gate to Kabul airport ahead of the deadly bombing, but kept it open to assist the British evacuation.

And he did not rule out the RAF taking part in air strikes to target the so-called Islamic State terror group in Afghanistan.

The US ended a deployment that began in the wake of the September 11 attacks two decades ago when it withdrew its remaining forces from Afghanistan on Monday.

Mr Raab did not dismiss the possibility that thousands of Afghans and UK nationals could have been left behind following the departure of British troops ahead of their American counterparts.

Instead, he told BBC Radio 4’s Today programme: “It’s very difficult to give you a firm figure. I can tell you that for UK nationals we’ve secured since April over 5,000, and we’re in the low hundreds (remaining).”

It is just not true to suggest that other than securing our civilians inside the airport that we were pushing to leave (Abbey Gate) open

The Foreign Secretary disputed leaked Pentagon notes obtained by the Politico website suggesting the US wanted to close Kabul airport’s Abbey Gate but kept it open to allow UK evacuees into the airport.

Mr Raab said it was “just not true” to suggest the UK called for the gate to be left open for part of its exit operation after the leak threatened to strain relations between Britain and the US.

Scores of Afghans, 13 US service personnel, two Britons and the child of a British national died in a bombing carried out by Isis-K, an Afghan offshoot of Islamic State.

“We co-ordinated very closely with the US, in particular around the Isis-K threat which we anticipated, although tragically were not able to prevent, but it is certainly right to say we got our civilians out of the processing centre by Abbey Gate,” Mr Raab told Sky News.

“But it is just not true to suggest that other than securing our civilians inside the airport that we were pushing to leave the gate open.”

With the threat of the terror cell remaining, Air Chief Marshal Sir Mike Wigston indicated the RAF could strike Isis-K targets in Afghanistan.

“Ultimately what this boils down to is that we’ve got to be able to play a global role in the global coalition to defeat Daesh, whether it’s strike, or whether it’s moving troops or equipment into a particular country, at scale and at speed,” he told the Daily Telegraph.

“If there’s an opportunity for us to contribute I am in no doubt that we will be ready to – that will be anywhere where violent extremism raises its head, and is a direct or indirect threat to the UK and our allies.”

Mr Raab declined to rule out such strikes.

“In extremis, we always reserve the right to exercise lawful self defence and we would, of course, never rule that out in particular in relation to dealing with terrorist groups,” he told Today.

The final US troops left Kabul on a flight shortly before midnight local time on Monday, ahead of President Joe Biden’s deadline to withdraw before the end of August.

The Taliban proclaimed “full independence” for Afghanistan after the US withdrawal.

One Kabul resident told the PA news agency he and his family were unable to sleep due to the noise of gunfire as the Taliban celebrated the departure of US troops.

The Afghan, who is not being named to protect his security, said the Taliban were shooting into the sky until 3.30am.

“Firing began when US last airplane took off from airport… we didn’t (sleep) because of gunshots,” he said.

He added that many people in the capital are already suffering from money, food and medicine shortages amid shop closures and border restrictions.

“Some of them (are) selling their house items to get some food or medicines for his or her family,” he added.

The new regime in Afghanistan faces pressure to respect human rights and provide safe passage for those who wish to escape its rule following the passage of a UN Security Council resolution.

The council adopted a resolution in New York – with Russia and China abstaining rather than wielding their vetoes – in what the UK hopes is a step towards a unified international response.

However, the resolution effectively acknowledges that it is now up to the Taliban to decide whether people can leave Afghanistan.