In a first sign of friction between the leaders of the two parties forming the core of the new government, Prime Minister Ehud Olmert and Defense Minister Amir Peretz sparred over the Labor Party leader's call to resume contacts with Palestinian Authority Chairman Mahmoud Abbas, officials said over the weekend. The premier and his defense minister held a heated meeting on the subject late Thursday night, after Peretz openly urged the government to restart negotiations with Abbas, commonly known as Abu Mazen, whom Olmert has shunned since forming his government earlier this month. "The issue of a meeting with Abu Mazen is not at the top of the prime minister's priorities," Olmert spokesman Assi Shariv said Saturday night. "It is not on the agenda at the moment." An Olmert decision on whether to meet with Abbas is only expected after his return from Washington at the end of the month. Abbas has previously suggested that Israel bypass Hamas and negotiate directly with him, but so far the government has said that it sees no point in holding negotiations with the weakened Palestinian leader if the Hamas-led Palestinian government refuses to moderate its ways. Shariv added that the prime minister had told Peretz that he will be the one to decide if and when to meet with Abbas. A Defense Ministry spokesman said Friday that Peretz did not dispute the fact that any decision on whether to negotiate with the PA chairman was the prime minister's to make. Peretz reiterated, however, that prior to the elections he had advocated talks with Abbas, and he was not prepared to change his views on the matter, his office said. The open dispute between the two men, which emerged one week after the new government was sworn in, could bode ill for its long-term stability and is an indication that Peretz is not going to hesitate to advocate his dovish views in public. Meanwhile, three of Olmert's top aides left for the US Saturday night to lay the groundwork for the prime minister's meetings with US President George W. Bush and other administration officials later this month. The advisers are Dov Weisglass and Shalom Turjeman, who have carried over in their jobs from prime minister Ariel Sharon's government, and attorney Yoram Turbowitz, an Olmert confidant. Olmert's first official visit to the United States as premier is to include a get-acquainted meeting with Bush at the White House on May 23, an address before a special joint session of Congress the next day, and meetings with Vice President Dick Cheney, Secretary of State Condoleezza Rice and Secretary of Defense Donald Rumsfeld. Olmert will try to garner American support for his convergence plan - whereby Israel would unilaterally withdraw from scores of isolated West Bank settlements while strengthening the major settlement blocs - and will focus on the Iranian nuclear threat. After returning from the US, Olmert will travel to Egypt for meetings with President Hosni Mubarak and King Abdullah of Jordan, while he is expected to visit Britain and France next month. However no meetings have been scheduled between Olmert and Abbas, although such a summit is seen as possible after the prime minister's meetings with Mubarak and Abdullah. Palestinian officials have previously said that Abbas and Olmert would meet after the premier's visit to Washington, but Israeli officials have denied any such plans. Last month, Israel broke off all ties with the Hamas-led Palestinian government, calling it a "hostile entity."