Islamabad, Jun 1 (IANS): Nawaz Sharif, who is set to become prime minister of Pakistan, Friday expressed strong reservations over US drone attacks inside Pakistani territory.

The drone strikes were not only violation of Pakistan's sovereignty but also against international laws and UN charter, reported Xinhua citing Sharif, the chief of Pakistan Muslim League-Nawaz (PML-N), in a statement.

The concern was conveyed to the US Charge d'affaires in Islamabad, said a spokesperson for Sharif.

The statement came a day after the Pakistani Taliban withdrew ceasefire offer as an unmanned drone killed Waliur Rehman, a Taliban leader, in North Waziristan tribal region near Afghan border.

The Taliban had offered peace talks to the new government, raising hopes for an end to the ongoing Taliban insurgency. But the US drone strike has now diminished the chance of dialogue. Rehman was believed to be a strong supporter of peace talks, according to Taliban leaders.

Earlier Friday, Chaudhry Nisar Ali Khan, a senior PML-N leader, said Sharif would devise a policy on the US drone attacks that are in violation of the country's national sovereignty.

All stakeholders would be taken into confidence before announcing the policy on drone attacks, he added.

On Sunday, PML-N had nominated its chief Nawaz Sharif for the post of prime minister, two weeks after the party won the general elections. But no date had been fixed for the first session of the National Assembly which will elect the prime minister.