TEHRAN (AFP) - Iranian President Mahmoud Ahmadinejad will on Tuesday host a summit with his counterparts from Afghanistan and Pakistan, which is expected to discuss rebuilding of war-shattered Afghanistan.

Announcing the summit on Saturday, Ahmadinejad's office did not reveal the agenda for the talks to be attended by Afghanistan President Hamid Karzai and President Asif Ali Zardari of Pakistan.

But the gathering comes less than three months after the three met in Tehran for a regional economic summit, along with leaders from other neighbouring states.

That summit pledged to help rebuild Afghanistan, and also the Gaza Strip after Israel's devastating military assault in December and January.

The May 19 meeting also comes soon after a US-backed international conference on Afghanistan in The Hague which was attended by Tehran following diplomatic overtures by arch-rival Washington towards the Islamic republic.

The Tehran talks are expected to discuss efforts to rebuild Iran's eastern neighbour which is battling a resurgent Taliban insurgency and also to find ways to rein in the rising violence in Pakistan.

The administration of US President Barack Obama has been working towards engaging Tehran in efforts to rebuild Afghanistan.

It is part of Obama's strategy to secure the help of Afghanistan's neighbours in reconstructing the Muslim country.

Iran has not had diplomatic relations with the US for nearly three decades, and was included in former president George W. Bush's so-called "axis of evil" along with North Korea and Iraq.

But since taking office in January, Obama and his top officials have approached Tehran diplomatically in a bid to break the deadlock over several issues concerning Iran and to secure its help in stabilising the region.

Shiite Iran, which has close ethnic and religious ties with Afghanistan, has long suffered from the effects of opium production in its eastern neighbour, with easily available heroin fuelling a rise in drug use at home.

Despite their rivalry, the US and Iran are both sworn enemies of the Taliban, a Sunni Muslim militia initially backed by Pakistan, that ruled Afghanistan from 1996 to 2001.

Tehran has been a vocal critic of Obama's strategy to increase US troops in Afghanistan, however.

At the March 31 economic conference, Iran's representative Mohammad Mehdi Akhoondzadeh warned that Obama's surge of US troops in Afghanistan was a mistake.

"The presence of foreign forces has not improved things in the country and it seems that an increase in the number of foreign forces will prove ineffective too," the Iranian deputy foreign minister told the gathering.

But Akhoondzadeh also said Tehran was "fully prepared to participate in the projects aimed at combatting drug trafficking and the plans in line with developing and reconstructing Afghanistan."

Afghanistan is the source of 90 percent of the world's heroin.