Taliban-linked militants threatening to kill three U.N. hostages accused the United States on Saturday of upsetting negotiations for their release.

Jaish-al Muslimeen (search), a spinoff from Afghanistan's former ruling militia, is demanding the release of 26 Taliban (search) suspects in exchange for the three foreign election workers, who were abducted more than two weeks ago.

The group, whose name means Army of Muslims, says all are in U.S. custody, some of them possibly in Guantanamo Bay, Cuba.

The United States has said it will not deal with kidnappers, a policy U.S. Deputy Secretary of State Richard Armitage (search) reaffirmed during a visit to Kabul earlier this week.

Mohammed Akbar Agha, the group's purported leader, said Armitage had dashed hopes that the hostages could be freed before the Islamic feast of Eid al-Fitr, which began Saturday.

"The negotiators from the Afghan government contacted us on Friday, and we discussed the whole situation," Agha told The Associated Press in a telephone call from an undisclosed location.

"We were hopeful that the issue would be resolved before Eid, but remarks by Richard Armitage caused some delay," he said. "We may take a final decision about their fate today."

Philippine diplomat Angelito Nayan, British-Irish Annetta Flanigan, and Shqipe Hebibi of Kosovo were seized at gunpoint on Oct. 28, the first abduction of foreigners in the capital since the fall of the Taliban three years ago.

The kidnappers released a video of the trio, reinforcing fear that Afghan rebels were copying their counterparts in Iraq, where insurgents have executed a string of Western hostages.

Afghan and U.N. officials have declined to comment on any negotiations involving either a prisoner swap or a ransom, even though the militants claim a deal is close.

Jaish-al Muslimeen spokesmen say they want the freedom of 15 men picked up near the southern border town of Spin Boldak a month ago and 11 more detained earlier.

President Hamid Karzai has led Afghan calls for the freeing of the hostages, who helped organize the Oct. 9 election which returned him as the country's first popularly elected leader.

After Saturday morning prayers in his Kabul palace, Karzai made no mention of the hostage crisis and declined to take questions.

But several worshippers at the city's main Eid Gah mosque said they were thinking of the missing U.N. staff.

"I prayed for the three hostages, particularly that Muslim woman (Hebibi), because she is Muslim," said Abdur Rahman, a 30-year-old electrician. "I hope the kidnappers out of respect for the holy month of Ramadan will release them safely."