The Bush administration renewed its call on Iran Monday to hand over, either to the United States or their countries of origin, members of al-Qaida it has in custody. But the State Department denied suggestions the United States has offered to exchange Iraqi-based Iranian opposition figures for members of the Osama bin Laden terrorist group.

The State Department says U.S. officials suspect that Iran has some senior operatives of al-Qaida in detention and says it is "essential" that the United States and other countries be given access to them and the information they may have about past and future plans of the terrorist organization.

The comments here came in response to a news report Sunday that Jordan's King Abdullah, who held talks in Washington late last week, has been trying to broker a deal under which Iran would hand over the al-Qaida members it has in exchange for Iranian opposition members under questioning by U.S. forces in Iraq.

U.S. troops in Iraq disarmed members of the Iranian group, the Mujahidin-e-Khalq or MEK, earlier this year when they moved into the area along the Iranian border where the group, officially designated a terrorist organization by the United States, had long been based.

But at a news briefing here, State Department spokesman Richard Boucher rejected the notion that a trade for Iranian-held al-Qaida members was being considered.

"The United States is not engaged in discussions regarding a swap of Mujahidin-e-Khalq members held by U.S. forces in Iraq in return for al-Qaida members held in Iran," he said. "The U.S. is questioning Mujahidin-e-Khalq members that are held by U.S. forces in order to determine whether any further legal proceedings are merited."

The U.S.-led invasion of Iraq put an end to military activity by the MEK, and the Bush administration has in recent months taken a tougher line toward the organization, in August shutting down U.S. offices of the group's nominally-independent political wing, the National Council of Resistance, and freezing its assets.

Spokesman Boucher said Iran has turned over some al-Qaida members to third countries in recent years, but said he is aware of no progress on the hand over of those currently detained, among whom he said may be members of the terror group's "top leadership."

Diplomats and Arab press reports have said those held by Iran may include, among others, the second-ranking al-Qaida operative, Ayman al-Zawahri, and Osama bin Laden's son, Saad.