ROME (AFP) - Security forces locked down central Rome on Thursday as world leaders including the Israeli and Palestinian presidents attended a celebration to mark the founding of the Italian republic in 1946. The Afghan, Argentinian and Russian presidents were also among the more than 80 international delegations taking part, along with US Vice President Joseph Biden, Chinese Vice President Xi Jinping and UN Secretary General Ban Ki Moon. Italian Prime Minister Silvio Berlusconi, on the defensive after his party's shock defeat in local elections, will be hosting talks with Biden and Russian President Dmitry Medvedev following a military parade on Thursday. Israeli military radio also reported the possibility of an impromptu "summit" in the Italian capital between Israeli President Shimon Peres, Palestinian president Mahmud Abbas and Biden. Peres said he was prepared to meet Abbas but acknowledged his visit came as part of Israeli efforts to convince European nations to oppose Palestinian plans to seek UN membership as a state in September. "There are differences of opinion between European countries. Europe is not united on this issue. That's why the moment has come to try to wield influence," Peres told Israeli radio.