The group so far has control over 18 provincial capitals across Afghanistan.
In his first appeal to the group, UN Secretary-General Antonio Guterres urged the Taliban to immediately halt the offensive and negotiate “in good faith” to avert a prolonged civil war.
“This is the moment to halt the offensive. This is the moment to start serious negotiation. This is the moment to avoid a prolonged civil war or the isolation of Afghanistan,” Guterres said at a press conference.
“Afghanistan is spinning out of control,” Guterres said. “Continued urban conflict will mean continued carnage – with civilians paying the highest price.”
Meanwhile the US and European countries are evacuating their embassy staff as the Taliban inch closer to the country’s capital, Kabul.
Violence has been surging across the war-torn country as provincial capitals fall to the Taliban one after another quickly as they press ahead with their offensive across Afghanistan.
On Thursday, Afghan government negotiators in Qatar offered the Taliban a power-sharing deal in return for an end to fighting amid the militants' rapid advances across the war-torn country.
The Taliban, however, have reiterated that they would not participate in any government shared with the Afghan government.
The US has been withdrawing forces from Afghanistan in a hasty plan devised after two decades of war and occupation.
Last year, former US president Donald Trump agreed to pull out forces from Afghanistan under a deal with the Taliban, in which they pledged not to attack the withdrawing foreign forces, but made no promise not to attack Afghan government forces or people.