"The invaders and their allies should understand that inking strategic agreement would be accompanied by dire consequences," Taliban's elusive chief Mullah Mohammad Omar said in a message posted on the outfit's website on the eve of Eid-ul Adha.
The Eid-ul Adha festival will be celebrated by Muslims across the world on Tuesday.
Omar, who has eluded the US's biggest military manhunt in the region over the past 12 years, in the message also warned that the people of Afghanistan would not accept any strategic agreement even if it got rubber stamped by "a fake Loya Jirga".
Afghan President Hamid Karzai and US Secretary of State John Kerry, after a 26-hour intense discussion here, announced at a joint press conference on Saturday night that differences over inking a security arrangement, known as the Bilateral Security Agreement (BSA), have been narrowed.
Mullah Omar: No foreign military base is acceptable to Afghans
The Afghan president revealed a couple of weeks ago that he would convene the traditional Loya Jirga or grand assembly of tribal chieftains, notables and government functionaries, probably within a month to take a final decision on the security agreement.
The controversial security accord, if inked, would facilitate the US to keep a limited number of its troops in Afghanistan beyond 2014 when the NATO-led forces would leave the conflict-ridden country.
"No foreign military base is acceptable to Afghans," Mullah Omar added in his statement, warning that having military bases would intensify armed jihad against foreigners in Afghanistan.