U.S. President Joe Biden told key allies in June that he would maintain enough of a security presence in Afghanistan to ensure they could continue to operate in the capital following the main U.S. withdrawal, a vow made before the Taliban’s rapid final push across the country, according to a British diplomatic memo seen by Bloomberg.

Biden promised U.K. Prime Minister Boris Johnson and other leaders at the Group of Seven summit in Cornwall, England, that "critical U.S. enablers” would remain in place to keep Kabul safe following the drawdown of NATO forces, the note said. British officials determined the U.S. would provide enough personnel to ensure that the U.K. embassy in Kabul could continue operating.

But the withdrawal of U.S. forces saw the Afghan government collapse as Taliban fighters raced across the country seizing provincial capitals, culminating in scenes of chaos at Kabul’s airport this week as Western governments tried to pull out their diplomats. The British Embassy has since been evacuated, Johnson’s office said, and the U.S. Embassy is now shuttered.