"The president said that he will take off his uniform before December 1 of this year," Malik Mohammad Qayyum told a news conference in the country's capital, Islamabad.
He also said a caretaker government would be sworn in on Friday, to ensure the smooth conduct of early parliamentary elections in January 2008.
General Musharraf seized power in a military coup in 1999. He has since retained his presidential and military titles, as well as the right to dissolve parliament and dismiss the government.
He won the October 6 presidential elections, but the results will only be officially announced after the Supreme Court rules on an opposition party petition alleging Musharraf, as the armed forces commander in chief, is not entitled to run for president.
Musharraf said that if officially recognized as president, he will resign from the military and become a civilian president.
He imposed a state of emergency in Pakistan on November 3, citing a dangerous rise in militant activity.
The president banned the Supreme Court from overturning the emergency order, blocked non-state TV broadcasts, and restricted people's movement in the country, measures which have been widely condemned by the international community.
But most Pakistanis and foreign diplomats believe General Musharraf's decision was aimed at preventing the Supreme Court from invalidating his reelection in October while he was still the army chief.
The United States and other Western nations condemned Musharraf's decision to impose emergency rule in the country.
