Pakistan's President Asif Ali Zardari is set to be at this weekend's Nato summit on Afghanistan.

The Pakistani embassy in Washington told the BBC he was "likely to attend" the meeting in Chicago.

Nato said Pakistan had an important role to play in its neighbour's future.

The move comes amid signs that Pakistan may be about to lift a blockade of Nato's ground supply lines to Afghanistan imposed in November, after a Nato air strike killed 24 soldiers.

The closure of the route, after the Pakistani soldiers were killed, left thousands of tankers bound for Afghanistan stranded in Pakistan.

BBC correspondents say Pakistani leaders may have decided the blockade of Nato shipments is counter-productive and has resulted in the country being sidelined in planning for Afghanistan's future.

Pakistan's government is also due to present its budget later this month, and badly needs US aid.

Pakistan stayed away from the last major summit on Afghanistan, which was held in Bonn in December.

'Levy'

Pakistani lawmakers unanimously approved new guidelines for bilateral ties with the US in mid-April. They demanded that the US provide an "unconditional apology" for the November attack and stop drone strikes.