Citing "tactical reasons" for the difficulty, he stressed it was not his intention "to stay there a long time".
Mr Biden said it was important that US service members leave Afghanistan in a safe and orderly manner, adding he is coordinating with NATO allies who also have troops in the region.
The deadline to remove the remaining 2,500 US troops was established under the Trump administration last year.
Mr Biden had previously said keeping to that timeline would be difficult.
Earlier this month, the US Secretary of State reportedly wrote to the Afghan President saying the US was considering the full withdrawal of forces by the 1 May deadline.
Antony Blinken called for urgent leadership in the stalled peace talks with the Taliban, after violence by the group against Afghans has soared in recent months.
Mr Blinken said: "When we look back at the past decades of our military involvement in the world, especially in Afghanistan and the Middle East, we must remember what we learned about the limits of force to build a durable peace."
Since the US-Taliban peace deal was signed in February 2020, 7,000 NATO troops – mostly American – have left Afghanistan.
The alliance has just missed a self-imposed deadline to decide to withdraw all troops under the terms of the peace deal.
British troops are deployed to Afghanistan in a non-combat role as part of a NATO mission.
Cover image: Joe Biden speaking at a virtual event hosted by the Munich Security Conference last month (Picture: PA).