KABUL, Afghanistan, (AP) – President Hamid Karzai offered to meet with the Taliban leader and give militants a government position, but a spokesman for the militant group on Sunday said it will “never” negotiate with Afghan authorities until U.S. and NATO forces leave the country.

Karzai made the offer only hours after a suicide bomber in army disguise attacked a military bus Saturday, killing 30 people — nearly all of them Afghan soldiers.

Strengthening a call for negotiations he has made with increasing frequency in recent weeks, Karzai said he was willing to meet with the reclusive leader Mullah Omar and Gulbuddin Hekmatyar, a former prime minister and factional warlord leader.

“If I find their address, there is no need for them to come to me, I’ll personally go there and get in touch with them,” Karzai said. “Esteemed Mullah, sir, and esteemed Hekmatyar, sir, why are you destroying the country?”

But the Taliban spokesman, Qari Yousef Ahmadi, repeated an earlier position by saying that it would never negotiate with the Afghan government in the “presence of foreign forces.”

“Even if Karzai gives up his presidency, it’s not possible that Mullah Omar would agree to negotiations,” Ahmadi told The Associated Press. “The foreign forces don’t have the authority to talk about Afghanistan.”

Karzai said he has contacts with Taliban militants through tribal elders but that there are no direct and open government communication channels with the fighters. Omar’s whereabouts are not known, although Karzai has claimed he is in Quetta, Pakistan, a militant hotbed across the border from Afghanistan’s Kandahar province.

“If a group of Taliban or a number of Taliban come to me and say, ‘President, we want a department in this or in that ministry or we want a position as deputy minister … and we don’t want to fight anymore,’ … If there will be a demand and a request like that to me, I will accept it because I want conflicts and fighting to end in Afghanistan,” Karzai said.

“I wish there would be a demand as easy as this. I wish that they would want a position in the government. I will give them a position,” he said.

The U.S. Embassy in Kabul has said it does not support negotiations with Taliban fighters, labeling them as terrorists, although the U.N. and NATO have said an increasing number of Taliban are interested in laying down their arms. NATO’s ambassador to Afghanistan, Daan Everts, said this month that the alliance would look into the possibility of talks.

President Bush met with Karzai on the sidelines of the U.N. General Assembly in New York on Wednesday where the two discussed the battle against al-Qaeda and the Taliban, but it has not been made public whether the two talked about negotiations with militants.

A State Department duty officer said he could not immediately comment on Karzai’s offer to meet with Omar, noting that most policymakers were still in New York.

Saturday’s explosion — the second deadliest since the fall of the Taliban in 2001 — ripped off the roof of the bus and tore out its sides in Kabul, leaving a charred hull of burnt metal. It was reminiscent of the deadliest attack since the U.S.-led invasion, when a bomber boarded a police academy bus at Kabul’s busiest transportation hub in June, killing 35 people.

Police and soldiers climbed trees to retrieve body parts. Nearby businesses also were damaged.

“For 10 or 15 seconds, it was like an atom bomb — fire, smoke and dust everywhere,” said Mohammad Azim, a police officer who witnessed the explosion.

Karzai said 30 people were killed — 28 soldiers and two civilians. The Health Ministry said another 30 were wounded. Two women were among the dead, and 11 people whose bodies were ripped apart so badly had yet to be identified.

“It was a terrible tragedy, no doubt an act of extreme cowardice,” Karzai said. “Whoever did this was against people, against humanity, definitely against Islam. A man who calls himself Muslim will not blow up innocent people in the middle of Ramadan,” the Muslim holy month.

A purported Taliban spokesman, Zabiullah Mujahid, claimed the militant group was responsible for the blast in a text message to The Associated Press. Mujahid said the bomber was a Kabul resident named Azizullah.

The bus had stopped in front of a movie theater to pick up soldiers when a bomber wearing a military uniform tried to board early Saturday, army spokesman Gen. Mohammad Zahir Azimi said.

“Typically there are people checking the IDs of soldiers who want to board the bus,” Azimi said. “While they were checking the IDs the bomber tried to get on the bus and blew himself up there.”

Karzai earlier this month renewed a call for talks with the Taliban. But he said Saturday he would not meet demands that foreign troops must first leave the country.

“It should be very clear that until all our roads are paved, until we have good electricity and good water, and also until we have a better Afghan national army and national police, I don’t want any foreigners to leave Afghanistan,” he said.

He said he still wanted negotiations with Taliban militants of Afghan origin “for peace and security.” He ruled out talks with al-Qaeda and other foreign fighters.

NATO’s International Security Assistance Force, meanwhile, said one of its soldiers was killed in eastern Afghanistan during combat operations on Saturday. ISAF did not release the soldier’s nationality, but most in the east are American.

Four employees with the International Committee of the Red Cross, kidnapped earlier this week while negotiating the release of a German hostage, were also freed Saturday, the ICRC said.

The four men — two Afghans, a Macedonian and a man from Myanmar — said they were treated well. A Taliban commander said he ordered the four held hostage because he thought they were spies but let them go once it was proven they were Red Cross workers, according to a video obtained by AP Television News.

The four had traveled to Wardak province in hopes of helping free a German man held since July. The workers said that the German was still alive and that they had seen him.

The number of kidnappings in Afghanistan has spiked in recent months after the Taliban secured the release of five insurgent prisoners in exchange for a captive Italian journalist in March — a heavily criticized swap that many feared would encourage abductions.

The Taliban kidnapped 23 South Koreans in July, a hostage crisis that scored the militants face-to-face talks with South Korean government delegates. Two of the Koreans were killed; 21 were eventually released.