"For the last two years, I've sent letters to the king of Saudi Arabia, and I've sent messages, and I requested from him as the leader of the Islamic world, for the security and prosperity of Afghanistan and for reconciliation in Afghanistan ... he should help us," Karzai said in a message to Afghans to mark the Muslim holiday of Eid al-Fitr.
Saudi Arabia is a leader of the Sunni Muslim world and the location of Islam's two holiest shrines in Mecca and Medina. It was one of a handful of countries that recognized the strictly Islamic Taliban as rulers of Afghanistan in the 1990s.
Even after their ouster by a U.S.-led invasion in 2001, Saudi kept its doors open for Taliban members to make the annual Muslim pilgrimage to Mecca and Medina.
While al-Qaida leader Osama bin-Laden, a Saudi, has frequently railed against the U.S.-allied kingdom, his sympathizers among the Afghan Taliban have been muted in their criticism.
Saudi officials, celebrating Eid al-Fitr on Tuesday, could not immediately be reached for comment.
Karzai, speaking at the presidential palace, said his government is trying to encourage militants to lay down arms. He said he has in the past reached out to fugitive Taliban leader Mullah Omar to "come back to your home soil and work for the happiness of the people."
The Taliban has largely rebuffed repeated peace overtures from Afghan officials.
Mullah Omar released his own Eid message with a barrage of accusations against Afghan security forces, calling them thieves, smugglers and criminals not worthy of the public's trust. He also called on militants not to harm civilians during their operations.
He did not indicate any willingness to talk to Karzai's government and called again on tens of thousands of American and NATO troops to leave the country.
A former senior Taliban official told The Associated Press last week that the militants do not consider Karzai a strong leader who can uphold and implement any potential deal if America does not agree with it. He spoke on condition of anonymity because he did not want to be identified.
U.S. officials have not indicated they are ready for any contacts with high-level Taliban leaders, though U.S. officials do encourage fighters to lay down arms and join the government's reconciliation program.
An Afghan opposition leader, former President Burhanuddin Rabbani, told The Associated Press earlier this year that Afghan political leaders have been meeting with Taliban and other anti-government groups in hopes of negotiating peace.
The contacts took place between leaders of the opposition National Front party and "high level" militant leaders.
Rabbani said some Taliban are willing to negotiate, but others are opposed.
Karzai said he would personally protect Taliban and other militant leaders from U.S. and NATO troops if they come back to Afghanistan for talks.
"Don't be afraid of the foreigners. If they try to harm you, I will stand in front of them," Karzai said.
Omar went into hiding after the Taliban regime was toppled.
Afghan officials have said he is hiding in or near the Pakistani city of Quetta but Pakistan claims he is in Afghanistan.
Also on Tuesday, the U.S.-led coalition said three of its troops were killed in a roadside bomb blast in southern Afghanistan.
The coalition did not release the nationalities of the troops or the blast's location. Most troops in the coalition are American but it does include forces from several other countries.
Taliban and other militant bombs have grown larger and more deadly this year. More U.S. soldiers have died in Afghanistan already this year than in any year since the 2001 U.S.-led invasion. At least 127 U.S. forces have died, as have 99 from other coalition countries.
