Afghan President Hamid Karzai on Monday gave a lukewarm response to Pakistan's invitation to visit Islamabad, setting conditions for any high-level talks designed to mend increasingly frosty relations.

Pakistan on Sunday sent its top diplomat to offer further assistance to Afghanistan's efforts to reach a deal with Taliban insurgents to end 12 years of war.

Afghanistan's parliament on Monday sacked Interior Minister Mujtaba Patang, one of the country's most powerful security chiefs, less than a year after he took office.

Patang lost a vote of confidence by 136 to 60 in the lower house of parliament over accusations of corruption and incompetence in the battle against Taliban insurgents.

A senior Pakistani official flew to Afghanistan on Sunday, inviting President Hamid Karzai to Islamabad as part of a charm offensive designed to improve strained relations and help peace efforts with the Taliban.

Foreign affairs adviser Sartaj Aziz is the most senior member of Pakistan's new government to visit Afghanistan.

President Hamid Karzai on Saturday approved a second law designed to pave the way for smooth transition of power in Afghanistan next year, easing Western concerns that key elections could be delayed.

Karzai's signature on the law, which determines how presidential and provincial votes will be run, follows pressure from donor nations determined to prove that the 12-year war and billions of dollars of aid money have not been in vain.

The United States is seriously considering speeding up the withdrawal of its forces from Afghanistan because of frustration with President Hamid Karzai, the New York Times reported.

And a so called 'zero option' -- having no U.S. troops in Afghanistan after 2014 -- is also on the cards, the daily said late Monday, quoting U.S. and European officials.

Gunmen on Thursday shot dead one of the most high-profile female police officers in Afghanistan, underlining the threat to women who take on public roles in the country.

Lieutenant Islam Bibi was a well-known face of female advancement, but admitted to receiving regular death threats from people who disapproved of her career -- including from her own brother.

Pakistan assured visiting British Prime Minister David Cameron on Sunday that it would promote efforts to reach a peace deal in neighboring Afghanistan before NATO's planned withdrawal.

Cameron is the first foreign government leader to visit Islamabad since Prime Minister Nawaz Sharif took office in June after winning landmark elections in May.

U.S. President Barack Obama and Afghan leader Hamid Karzai support the idea of holding talks with the Taliban in its Qatar office, the White House said Tuesday, reviving hopes for a peace process.

The announcement came despite a brazen Taliban assault on the Afghan presidential palace in the heart of Kabul Tuesday, in which three security guards and all five assailants were killed in an hour-long gunbattle.

U.S. envoy James Dobbins arrived in Islamabad on Tuesday for talks with Prime Minister Nawaz Sharif and other senior officials on efforts to open peace talks with Afghan Taliban, Pakistan's Foreign Ministry said.

Dobbins, who flew in from Kabul, will meet Sharif and "brief us on developments relating to Afghanistan," Foreign Ministry spokesman, Aizaz Ahmad Chaudhry told AFP.

U.S. envoy James Dobbins was set for talks with Afghan President Hamid Karzai in Kabul later Monday, officials said, as Washington works to put peace efforts back on track after a dispute over the rebels' new office in Qatar.

Karzai reacted furiously to the office being styled as a Taliban government-in-exile under the white flag and using the formal name of the "Islamic Emirate Of Afghanistan" from their hardline 1996-2001 regime.