US President Joe Biden's refusal to extend the withdrawal of American troops from Afghanistan beyond his self-imposed deadline of Tuesday next week was a point-blank rejection of calls from G7 and European leaders.

       They had appealed for US forces to be kept on at Kabul airport for longer, despite the Taliban's insistence that evacuation flights must end by August 31.

       Bereft of US support, Washington's allies pledged to continue trying to get people out and help Afghans who are left behind. But they had already admitted it will be impossible to complete the process in time.

       Over the past 10 days thousands of foreign nationals and Afghans with connections to Western organisations have been airlifted out of the country. But for thousands more, desperate to flee the Taliban, the exit is barred.

       Afghanistan: Biden sticks to Kabul withdrawal deadline rejecting Europe's appeals

       "We will go on right up until the last moment that we can," said Boris Johnson, after Tuesday's virtual meeting of G7 leaders failed to sway Washington. "But you’ve heard what the president of the United States has had to say, you’ve heard what the Taliban have said."

       The British Prime Minister had openly lobbied to keep the airport presence after the end of the month. The UK has around 1,000 troops at Kabul airport, supporting nearly 6,000 US forces. Other countries including France, Germany and Turkey are also present in smaller numbers.

       A senior French official said President Macron had pushed for the US deadline to be extended, but would “adapt” to the American sovereign decision. "That’s in the hands of the Americans," he said.

       The German chancellor was candid about Europe's powerlessness in the face of the US withdrawal. "I want to stress again that of course the United States of America has the leadership here," Angela Merkel told reporters in Berlin. "Without the United States of America, for example, we -- the others -- cannot continue the evacuation mission."

       G7: Europe's leaders fail to convince Biden to extend Afghanistan troop withdrawals Access to Kabul airport must be secured 'for as long as necessary' — EU

       Europe's leaders vowed to continue trying to help the Afghan people -- although without any military presence, exactly how is a moot point -- and prepare the ground for an eventual influx of refugees heading west.

       "It is our moral duty to help the Afghan people and provide as much support as conditions allow," EU Commission President Ursula von der Leyen said on Twitter.

       Charles Michel, President of the European Council representing national leaders, tweeted to say the evacuation of foreign and local staff remained an "immediate priority". He called for "wider G7 engagement and international action in support of Afghan people".

       He also focused on security, citing the need to prevent the "resurgence of terrorism".

       "Cooperation with countries in the region will be key in supporting the safety and proper living conditions of Afghans fleeing their country," he tweeted. "We are determined to keep migratory flows under control and EU's borders protected."

       After Tuesday's G7 meeting, Biden insisted that the US and its closest allies would “stand shoulder to shoulder” in future action over Afghanistan and the Taliban.

       In a partial show of unity, G7 leaders agreed on conditions for recognising and dealing with a future Taliban-led Afghan government.

       But the outcome of the meeting of the leaders of Britain, Canada, France, Germany, Italy, Japan and the US was a resigned acknowledgment from European powers that Washington calls the shots.

       For some commentators, the debacle of the US and Western withdrawal from Afghanistan has plunged relations between America and Europe to their lowest ebb in decades.