Iran has said it has arrested a number of members of the al-Qaeda network, but that they are not high level operatives.
Riyadh attack: US officials suspect an Iranian connection
The announcement comes amid intense pressure on Iran from the United States, which alleges that Tehran is allowing terrorists safe haven in the Islamic republic.
Iran rejects that charge. Foreign Minister Kamal Kharrazi told a government television station that Iran had been "the pioneer in fighting al-Qaeda terrorists, who have been posing threats to our national interests".
Washington says there is a link between Iran and the attacks in Riyadh, Saudi Arabia, earlier this month, which killed 34 people including nine suicide bombers.
The US is reported to have cut off behind-the-scenes talks with Iran since the Riyadh attacks.
US officials from a range of departments are meeting on Tuesday to discuss Washington's Iran policy.
The Washington Post newspaper said the officials would consider a Pentagon plan to destabilise the country.
The issue has reportedly revived the split between moderates in the Bush administration who favour diplomacy and hardliners who prefer more robust action.
President George W Bush listed Iran as one of three countries in an "axis of evil" last year, but relations warmed slightly in the wake of the war in Afghanistan.
Lately, however, they have become more tense, the BBC's Jim Muir in Tehran says.
Areas of dispute
Washington accuses Tehran of harbouring al-Qaeda members, of working towards building nuclear weapons, and of interfering in US reconstruction programmes in Iraq.
Tehran has strongly denied all of Washington's charges.
It suspects that hardliners in the US administration are trying to pave the way for moves to undermine or change Iran's Islamic system, our correspondent says.
Iranian officials insist that they have detained and expelled more than 500 al-Qaeda suspects over the past year.
Mr Kharrazi says Iran has been fighting al-Qaeda for years
But they admit that al-Qaeda suspects could be in the country without Iranian authorities being aware of it.
"Our borders with Afghanistan and Pakistan are so long that some al-Qaeda members have sought refuge in Iran," Mr Kharrazi told the French newspaper Le Figaro on Monday.
"We have arrested many of them and extradited them to their country of origin," he said.
'Issue is clear'
Richard Myers, the chairman of the US Joint Chiefs of Staff and America's highest ranking military officer, told US television the "issue with Iran is pretty clear".
"We have to eliminate the safe havens where the terrorists are, and Iran of course has some of the al-Qaeda members," he told NBC television.
Mr Myers said he was "probably" attending the administration meeting on Tuesday but offered no further details.
"I'll know more after we have that meeting," he said.