An Arab satellite station carried a statement Thursday allegedly from the vanished Taliban leader Mullah Mohammed Omar in which he vows to drive U.S. forces from Afghanistan.

Qatar-based Al-Jazeera as well as a prominent Islamic Internet site -- both known for obtaining material linked to Islamic militants -- carried the statement, which was dated to coincide with the Sept. 11 terror attacks anniversary but first appeared Thursday.

It was impossible to verify the statement's authenticity or how the pan-Arab station or Web site obtained it. Al-Jazeera officials weren't immediately available for comment.

"We told our [Islamic] community ... that we are not afraid of [President] Bush's and America's threats," the statement said. "We are continuing jihad [holy war] against America and all the invaders ... We reassure Muslims everywhere that we are abiding by the pledge, and that victory is coming."

Mullah Omar's radical Taliban government was toppled in U.S-led war on terror following the Sept. 11 attacks. The Taliban had offered sanctuary to Usama bin Laden and his Al Qaeda forces.

Mullah Omar, bin Laden and several of their lieutenants disappeared during the fighting in Afghanistan last year and officials in various governments have given conflicting statement on whether they're believed alive or dead.

In the latest such comment, Afghan President Hamid Karzai told ABC's Good Morning America program Thursday that he believes Omar is alive. "A lot of times we are very close to capturing him," he said.

Karzai also said that bin Laden is probably dead. "The more we do not hear of him or see any signal of his whereabouts or survival or otherwise, we are likely to believe he is not alive," Karzai said.

Last month, Afghanistan's foreign minister said he believed bin Laden and Mullah Omar were hiding in northwest Pakistan, but Pakistani officials have said repeatedly that they do not believe they are on Pakistani soil.

According to the statement, Mullah Omar said Sharia -- or Islamic -- law will return to Afghanistan and "America won't enjoy Afghanistan or find comfort in it until it will leave ashamed."

Meanwhile, al-Jazeera on Thursday continued its coverage of the Sept. 11 attacks anniversary, featuring interviews with two top Al Qaeda officials wanted for their roles in the strikes on New York and Washington.

Yosri Fouda, the presenter of Al-Jazeera TV's investigative program Top Secret, said the Al Qaeda members told him during interviews conducted in Pakistan in June that they had considered attacking the White House on Sept. 11, "but it was later ruled out for navigational reasons." He did not elaborate.

On Tuesday, Fouda told The Associated Press he was taken, blindfolded, to a secret location in Pakistan to meet Khalid Shaikh Mohammed and Ramzi Binalshibh.

U.S. officials regard Mohammed as one of the highest-ranking Al Qaeda leaders still at large and believe he is still planning attacks against U.S. interests. U.S. officials say Binalshibh was a member of a Hamburg-based cell led by Mohammed Atta, the Egyptian-born suspected lead Sept. 11 hijacker.

In an article for London's Sunday Times article, Fouda wrote that he learned during the interviews that the U.S. Congress had been Al Qaeda's fourth Sept. 11 target. Hijacked planes slammed into the World Trade Center towers and the Pentagon, while one crashed in a Pennsylvanian field after passengers apparently stormed the hijackers.

In Thursday's broadcast, Al-Jazeera aired audio excerpts of Fouda's interview, in which two male voices attributed to Mohammed and Binalshibh revealed details about the buildup to the Sept. 11 attacks.

The voice purported to be Binalshibh's said the hijackers were instructed to take over the planes 15 minutes after takeoff. "That was the best time, and they were very brave," he said.