Aug 24 (Reuters) - Western troops at Kabul airport worked frantically on Tuesday to evacuate people from Afghanistan before an Aug. 31 deadline as U.S. President Joe Biden faced growing pressure to negotiate more time for the airlift of thousands trying to flee. Leaders of the Group of Seven (G7) countries - Britain, Canada, France, Germany, Italy, Japan and the United States - were due to meet virtually on Tuesday to discuss the crisis. British Prime Minister Boris Johnson is expected to push for a deadline extension. Chaos punctuated by sporadic violence has gripped the airport, with foreign troops and Afghan security guards driving back crowds clamouring to get on flights following the Taliban"s takeover of the Afghan capital on Aug. 15. Countries that have evacuated some 58,700 people over the past 10 days were trying to meet the deadline agreed earlier with the Taliban for the withdrawal of foreign forces, a NATO diplomat told Reuters. loading "Every foreign force member is working at a war-footing pace to meet the deadline," said the official, who declined to be identified. Biden, who has said U.S. troops might stay beyond the deadline, has warned the evacuation was going to be "hard and painful" and much could still go wrong. A Taliban official said on Monday an extension would not be granted, though he said foreign forces had not sought one. Washington said negotiations were continuing. CIA Director William Burns met Taliban leader Abdul Ghani Baradar in Kabul on Monday, two U.S. sources told Reuters. Democratic U.S. Representative Adam Schiff, chairman of the House of Representatives Intelligence Committee, told reporters after a briefing by intelligence officials that he did not believe the evacuation could be completed in the days remaining. "It"s possible but I think it"s very unlikely given the number of Americans who still need to be evacuated," Schiff said. loading British defence minister Ben Wallace told Sky News he was doubtful there would be a deadline extension. But German Foreign Minister Heiko Maas said Germany was working with the United States and Britain to ensure the NATO allies can fly civilians out after the deadline. "Even if the deadline is Aug. 31 or is extended by a few days, it will not be enough to evacuate those we want to evacuate and those that the United States wants to evacuate," Maas told Bild newspaper. "That"s why we are working with the United States and Britain to ensure that once the military evacuation is completed it is still possible to fly civilians out of Kabul airport." In Moscow, Russian Foreign Minister Sergei Lavrov said the Kremlin was interested in serving as a middleman in resolving the crisis along with China, the United States and Pakistan. U.S. Marines provide assistance at an Evacuation Control Checkpoint (ECC) during an evacuation at Hamid Karzai International Airport, Afghanistan, August 22, 2021. Picture taken August 22, 2021. U.S. Marine Corps/Staff Sgt. Victor Mancilla/Handout via REUTERS/Files Families begin to board a U.S. Air Force C-17 Globemaster III transport plane during an evacuation at Hamid Karzai International Airport, Afghanistan, August 23, 2021. U.S. Marine Corps/Sgt. Samuel Ruiz/Handout via REUTERS. A child waits with her family to board a U.S. Air Force Boeing C-17 Globemaster III during an evacuation at Hamid Karzai International Airport, Afghanistan, August 22, 2021. U.S. Marine Corps/Sgt. Samuel Ruiz/Handout via REUTERS 1/7 Families begin to board a U.S. Air Force C-17 Globemaster III transport plane during an evacuation at Hamid Karzai International Airport, Afghanistan, August 23, 2021. U.S. Marine Corps/Sgt. Samuel Ruiz/Handout via REUTERS. loading At the same time, he said, Russia opposes the idea of allowing Afghan refugees to enter the ex-Soviet region of Central Asia or having United States troops deployed there. "If you think that any country in Central Asia or elsewhere is interested in becoming a target so that the Americans could fulfil their initiatives, I really doubt anyone needs that," Lavrov said during a visit to Hungary. RED LINE The frantic evacuation operation kicked off after the Taliban seized Kabul on Aug. 15 and the U.S.-backed government collapsed as the United States and its allies withdrew troops after a 20-year presence. The militant group had been ousted by U.S.-led forces in the weeks after the Sept. 11, 2001, attacks on the United States by al Qaeda militants whose leaders had found safe haven in Afghanistan. Many Afghans fear reprisals and a return to a harsh version of Islamic law that the Taliban enforced when in power from 1996 to 2001, in particular the repression of women. The top U.N. human rights official, Michelle Bachelet, said she had received credible reports of serious violations committed by the Taliban, including summary execution of civilians and restrictions on women and protests against their rule. read more "A fundamental red line will be the Taliban"s treatment of women and girls," she told an emergency session of the Human Rights Council in Geneva. An Afghan diplomat from the former government told the forum that millions of people feared for their lives amid reports of door-to-door searches. China"s U.N. envoy said the U.S. army and its partners should be held accountable for rights violations they committed in Afghanistan. The G7 leaders could discuss taking a united stand on the question of whether to recognise a Taliban government, or alternatively renew sanctions to pressure the Islamist militant movement to comply with pledges to respect women"s rights and international relations. "The G7 leaders will agree to coordinate on if, or when, to recognise the Taliban," said one European diplomat. "And they will commit to continue to work closely together." Leaders of the Taliban, who have sought to show a more moderate face since capturing Kabul, have begun talks on forming a government that have included discussions with some old enemies from past governments, including a former president, Hamid Karzai. The Pajhwok news agency reported that Taliban officials had been appointed to various posts including a governor of Kabul, acting interior and finance ministers and intelligence chief. A Taliban spokesman was not available for comment. Recognition of a Taliban government by other countries would have important consequences, like allowing the Taliban access to foreign aid that previous Afghan governments have depended upon. Biden has faced widespread criticism over the withdrawal, which was initiated by his Republican predecessor, Donald Trump, under a deal struck with the Taliban, and his opinion poll ratings have slipped. While Western countries have been trying to get people out, humanitarian agencies are struggling to get aid in. The World Health Organization only has enough supplies in Afghanistan to last for a week, an agency official said.