In a bid to defuse tensions between India and Pakistan, United States on Monday rushed its top Army official to Islamabad, to hold discussions with the country's political leadership.

US Joint Chiefs of Staff Admiral Mike Mullen arrived in Islamabad today on an unscheduled visit, second after the November 26 terror strikes in Mumbai that killed more than 180 people.

Mullen is scheduled to meet Pakistan President Asif Ali Zardari and Army Chief General Ashfaq Parvez Kayani. The US had recently criticised Pakistan for not doing enough to combat terror within its border.

Mullen met Pakistani national security advisor Mehmood Ali Durrani shortly after his arrival from Afghanistan and is expected to meet Kayani later. Admiral Mullen had visited Pakistan shortly after the attacks in India's financial capital.

He had then asked Pakistan to take action against elements involved in the Mumbai attacks. Besides discussing the regional security situation, Mullen is also expected to hold talks on the situation along the border with Afghanistan and the war on terror.