
Taliban spokesman Zabihullah Mujahid also repeated a long-standing demand for foreign forces to leave the country, saying reports of peace talks when troops were still battling insurgents on the ground would only undermine the credibility of the government and its foreign backers.
"The Islamic Emirate of Afghanistan, as in the past, refutes these futile claims," Mujahid said in a statement.
"If the enemy... insists on continuation of the war in the battlefields but on the other hand merely disseminates propaganda and contradictory claims about high-level talks, then it will only contribute first and foremost to the enemy's already losing credibility," he added.
The Washington Post reported earlier this month representatives of the Taliban and Karzai's government had started secret talks, citing unnamed Afghan and Arab sources.
The sources were quoted as saying they believe the Taliban representatives were authorised to speak for the Quetta Shura, the Afghan Taliban organisation based in Pakistan, and its leader.
Karzai said in an interview earlier this week his government had "unofficial contacts" with the Taliban over possible negotiations. But there were no direct negotiations for the moment, he said.
U.S. Ambassador Richard Holbrooke in Berlin on Monday also warned against over-emphasising Karzai's contacts with members of the Taliban, although they have been ongoing for some time.
Mujahid said talks would be a betrayal of the movement's fighters. Karzai has set up a scheme to try and lure low level Taliban off the battlefield and back to civilian life.
"You should have trust in your leadership and assure you that your leadership will not allow anyone to trade on your blood and sacrifices by reaching any clandestine deal," Mujahid said.
The insurgents also said the role of former Taliban officials in a High Peace Council set up by Karzai had no significance.
"If you think that a minuscule numbers of former officials of the Islamic Emirate who have already surrendered ... or those who were at first detained by you and now are living in Kabul under surveillance are representatives of the Islamic Emirate... then you should know that they are not," the Taliban said.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ