ISLAMABAD, June 25 (Xinhua) -- Pakistan Thursday asked the United States to review its policy of drone attacks in its northwest tribal region, saying the attacks are counterproductive.

"We would continue to convey the concern of the people of Pakistan to the United States," Foreign Office spokesman Abdul Basit said at weekly press briefing in Islamabad.

Earlier this week U.S drone aircraft struck two areas in South Waziristan bordering Afghanistan, killing 60 people, including the participants of a funeral of a slain Taliban commander.

"We have conveyed our serious concerns over the continued drone attacks to the United States. These are not acceptable and must be stopped," the spokesman said.

Pakistani Prime Minister Yousaf Raza Gilani also called for stopping the drone attacks in order to ensure success of Pakistan's strategy for isolating the militants from the tribes, when meeting U.S. National Security Advisor James Jones on Thursday.

The U.S has intensified drone attacks on the tribal regions despite Pakistan's protest at a time when the security forces are engaged in major offensive against Pakistan Taliban leader Baitulalh Mahsood in South Waziristan.

Last month, U.S. CIA director Leon Panetta defended the use of unmanned aircraft to target Al-Qaeda militants and said President Barack Obama's policies had severely disrupted the network's leadership.

Pakistani officials said that the drone strikes have killed more than 390 people in about 42 attacks since August 2008.