Pakistan's powerful army chief General Ashfaq Kayani on Sunday confirmed he will retire next month at the end of his second tenure, ending rumours he would seek to keep a key military role.

Kayani, who oversaw Pakistan's first democratic transfer of power, will retire on November 29 in a move likely to be seen as pushing forward the country's development as a democracy.

"It is time for others to carry forward the mission of making Pakistan a truly democratic, prosperous and peaceful country that embodies the finest dreams our founding fathers had envisaged for us," he said in a statement.

Kayani was appointed Chief of the Army Staff in 2007 and was given an additional three-year term in 2010.

Pakistan's army chief is considered the most powerful man in the country, commanding a force of around 600,000 and guiding policy in defence as well as in foreign and home affairs.

The country has suffered three coups and been ruled for more than half of its 66-year history by the military.

But Kayani is generally seen as a supporter of democracy, who helped the country complete its first democratic transition of power earlier this year and has also led the military in the so-called war on terror.

He played a key role in convincing former dictator General Pervez Musharraf to resign in 2008 and pushing then president Asif Ali Zardari to reinstate sacked judges in 2009.

"I share the general opinion that institutions and traditions are stronger than individuals and must take precedence," he said in his statement.

"As I complete my tenure the will of the people has taken root and a constitutional order is in place. The armed forces of Pakistan fully support and want to strengthen this democratic order."

Prime Minister Nawaz Sharif will announce a new army chief, who will take on the problems of Islamist militants and renewed border tensions with India.