Western powers are increasingly concerned not only by the Taliban's advances in Afghanistan but also by its growing influence in Pakistan, where Muslim fighters have disrupted Nato's supply convoys to Afghanistan and are securing concessions from the government in Islamabad.
Biden said Barack Obama, the US president, wanted to consult with allies on a strategy review for the region and that Washington would "expect everyone to keep whatever commitments were made in arriving at that joint strategy".
The vice-president said the September 11, 2001 attacks on the US and the bombings in Madrid in 2004 and London in 2005 were planned "from the very same mountains" along the Afghan-Pakistan border.
He said: "This is not a US-centric view. A terrorist attack in Europe is viewed as an attack on us."
Regarding discussions with Taliban moderates, Biden said: "It's worth exploring. The idea of what concessions would be made is well beyond the scope of my being able to answer.
"I do think it's worth engaging and determining whether or not there are those who are willing to participate in a secure and stable Afghan state."
Earlier on Tuesday, Biden held talks with Jaap de Hoop Scheffer, the Nato secretary- general.
De Hoop Scheffer, calling on Nato to boost efforts before Afghan elections due in August, said: "It is important that this alliance delivers in the short-term."
Last month, Obama approved the deployment of 17,000 more troops to Afghanistan as Washington and other Nato nations try to stabilise the country.
There are currently about 70,000 foreign troops in Afghanistan, of which the US supplies 38,000.
Obama has said he will make announcements about US policy on Afghanistan before a Nato summit in France in April.
The policy review is expected to stress the need for better co-ordination of the international effort and enhanced efforts in areas like police training, governance and development as well as a regional approach involving Afghanistan's neighbours.