United States Assistant Secretary of State Richard Boucher has arrived in Pakistan to discuss terrorism issues in the aftermath of the Mumbai attacks, a senior diplomat said here on Monday. He said that Boucher will meet President Asif Ali Zardari, Prime Minister Yousuf Raza Gilani and senior officials to deliberate on Pakistan's relationship with India after the 26/11 attacks in Mumbai. The US official in charge of South Asia in the outgoing Bush Administration will also meet opposition leaders, including Pakistan Muslim League-Nawaz (PML-N) chief Nawaz Sharif, said the diplomat. Besides Boucher, US vice-president-elect Joseph Biden will be arriving here on a two-day visit later this week to defuse tension between Pakistan and India after the Mumbai terror attacks. A high-level congressional delegation accompanying Biden will meet Zardari and Gilani to discuss the war on terror in Pakistan, its relations with India and a $15 billion aid package for Islamabad. US is pressing upon Pakistan to act in the light of "evidences provided to Islamabad by the Indian authorities regarding the Mumbai attacks and involvement of Pakistan-based militant groups", said the diplomat. Sources said that India has also asked the Pakistan High Commission in New Delhi to claim the nine dead bodies of the attackers who were killed by the Indian security forces during the attack. "We can't say if Boucher's is the last visit from the officials of the outgoing US administration. Still there are two weeks and another official may also visit Islamabad," said an official of the foreign ministry. The official also said that Zardari will visit Washington later this month to "personally congratulate president-elect Barack Obama after he takes oath on January 20".