US Secretary of State Condoleezza Rice has said she found Pakistan's leaders 'focused and committed' in helping India probe attacks in Mumbai.
The attacks had raised tension between the two countries.
Ms Rice had talks with President Asif Ali Zardari, Prime Minister Yousuf Raza Gilani and senior army officials.
She flew into Islamabad from New Delhi to try to defuse tension between India and Pakistan after New Delhi blamed elements in Pakistan for the last week's attacks in India's commercial hub.
The Secretary of State departed from Pakistan at around 1.30pm (8.30am Irish time).
India has blamed groups based in Pakistani territory for the attacks in which nearly 200 people were killed. Militants with guns and grenades lay siege to hotels and other sites in the city for 60 hours.
Dr Rice, who had earlier ended a visit to India, said both countries needed to make sure that their response did not lead to more attacks or other unintended consequences.
Meanwhile, India has declared a security alert at three major airports, including Delhi and the IT hub, Bangalore.
Extra checks to vehicles and luggage have been put in place after warnings from intelligence agencies.
Local television showed armed police guarding entrances to Delhi's international airport. Police cordons had also been set up outside the airport in the southern industrial city of Chennai.
