Updated

Pakistan summoned the U.S. ambassador to reject allegations in a Pentagon report that Islamabad supports militant proxies in neighboring India and Afghanistan as Pakistan's army chief met with the Afghan president in Kabul on Thursday to discuss how to enhance cooperation in the fight against militants.

According to the Foreign Ministry in Islamabad, Pakistani National Security and Foreign Affairs adviser Sartaj Aziz conveyed the complaint to U.S. Ambassador Richard Olson in a meeting at the ministry.

The U.S. Defense Department report, entitled "Progress Towards Security and Stability in Afghanistan," said militants continue to enjoy safe havens in Pakistan, which uses the fighters as a hedge against its loss of influence in Afghanistan and as a counterweight to India's superior military.

Pakistan said the allegations are of particular concern now as its military is waging a major offensive against militants in North Waziristan, a tribal region bordering Afghanistan. Pakistan launched the long-awaited operation in June, following years of allegations that it was turning a blind eye to cross-border attacks from Pakistan on Afghan and NATO security forces.

Islamabad has always denied the allegations, and has accused Kabul of hosting militants that carry out attacks in Pakistan.

The Pentagon report lauded the latest Pakistani military push and acknowledged that the army had made gains against local and foreign militants. But Pakistan's foreign ministry said the report was "unsubstantial" while noting Pakistan's cooperation with the U.S. in areas of mutual interest.

Pakistan has been at war for more than a decade with the Pakistani Taliban, an offshoot of the Afghan extremist group that Islamabad had supported in the past. Last weekend, a suicide bomber set off his explosives near a Pakistani paramilitary checkpoint on the border with archrival India, killing 61 people.

Also Thursday, Pakistani army chief Raheel Sharif traveled to Kabul, where he held separate meetings with the new Afghan President Ashraf Ghani and senior military leaders.

According to a statement by the Pakistan army, Sharif congratulated Ghani for being elected as the new president and reiterated that a "peaceful and stable Afghanistan was in Pakistan's best interest and the only way to ensure regional security was to treat terrorism as our common enemy."

Later, Afghan officials briefed Sharif about the latest security situation in Afghanistan.

During his meetings with the Afghan defense and military officials, Sharif "offered full range of training courses and facilities in Pakistan's training institutions to Afghan security forces," the statement said.

In Kabul, Ghani's office said the Afghan president told the visiting Pakistani army chief that Pakistan and Afghanistan should "honestly and together take action against common enemy." Ghani also called for enhanced cooperation between the two sides to ensure peace and stability in the region.