President Pervez Musharraf swore in Yousuf Raza Gilani as prime minister Tuesday, as two top US envoys held talks with Pakistan's old and new leaders. A key figure in the new government said it would review Musharraf's strategy against extremism and that Pakistan - wracked by suicide bombs - must not be sacrificed to ease terrorist threats elsewhere. Gilani, who will front the incoming civilian-led administration, took the oath from the US-backed president at a stiff ceremony in Islamabad. Seated side-by-side on a raised dais and flanked by two honor guards with white and gold-braided uniform, Gilani followed Musharraf's lead in reading the oath of office. Musharraf betrayed no emotion during the ceremony but gave Gilani a firm handshake and chatted amiably with him. “I congratulate Yousuf Raza Gilani and my cooperation will always remain with him,” Musharraf told state-run television afterward. Gilani appealed for national unity to tackle the crises facing Pakistan, particularly economic problems. “We have to give supremacy to the parliament so that we can jointly take the country out of these crises,” he said. American Deputy Secretary of State John Negroponte and Assistant Secretary of State for South Asia Richard Boucher arrived in Islamabad early Tuesday and held talks with Sharif just as the new premier was being sworn in. They then visited Musharraf at the presidential palace. While the envoys made no public comment, Sharif said he told them that it was “no longer a one-man show in Pakistan” and that the new parliament would decide after exhaustive debate how Pakistan should tackle extremism. He lashed out at Musharraf's US-backed policies, saying they had resulted in a wave of suicide bombings that killed Benazir Bhutto and many others, and argued that the security of Pakistan must not be sacrificed in order to protect other countries. Meanwhile, Pakistan's army chief has made changes to important posts in the military. The changes by army chief General Ashfaq Kayani, announced late on Monday, were the first major reshuffle in the army's top ranks since Musharraf stepped down as army chief in November. Lt. Gen. Shafaat Ullah Shah, a close confidante of Musharraf, was replaced as commander of a Lahore-based corps. Shah was appointed chief of logistics staff at army headquarters and was replaced by Lt. Gen. Ijaz Ahmed Bakhshi, the military said in a statement. Lt. Gen. Sajjad Akram, the commander of another corps based in the city of Mangla, was appointed deputy head of a government agency set up to oversee rehabilitation in areas devastated by an October 2005 earthquake. The former deputy of the earthquake rehabilitation agency, Lt. Gen. Nadeem Ahmed, was made commander of the Mangla-based corps. - With input from Agencies __