LONDON - World leaders hailed Hosni Mubarak's decision on Friday to step down as Egyptian president after 30 years in power, saying they shared the joy of Egyptians and hoped the transition to democracy would be peaceful. “Today is a day of great joy,” German Chancellor Angela Merkel told a news conference. “We are all witness to historic change. I share the joy of people on the streets of Egypt.” The most eagerly anticipated reaction was expected from Washington, where President Barack Obama was due to make an address later on Friday. The White House said he watched scenes from Cairo on TV after being told Mubarak stepped down. Vice President Joe Biden called it a “pivotal” moment in the history of Egypt and the Middle East. European foreign policy chief Catherine Ashton said: “By standing down, (Mubarak) has listened to the voices of the Egyptian people and has opened the way to faster and deeper reforms.” “It is important now that the dialogue is accelerated, leading to a broad-based government which will respect the aspirations of, and deliver stability for, the Egyptian people.” Switzerland said it was freezing assets potentially belonging to the former Egyptian leader. A senior Israeli official said Israel hoped Mubarak's resignation would not bring any change to relations with Cairo. Officials in Israel have expressed worry that Mubarak's successors might distance themselves from the peace treaty between the two countries, one of the cornerstones of Middle Eastern diplomacy but unpopular with many Egyptians. “It's too early to foresee how (the resignation) will affect things,” the official said. “We hope that the change to democracy in Egypt will happen without violence and that the peace accord will remain.” Germany's Merkel also called on Egypt to respect the treaty with Israel and said those now in charge should ensure that developments were “irreversible and peaceful”. In Gaza, the Palestinian enclave that has been jointly blockaded by Israel and Mubarak's Egypt, residents let off fireworks and fired guns into the air in celebration. Sami Abu Zuhri, spokesman for Hamas, the Islamist militant group that controls Gaza, called on Egypt's new leaders to lift the blockade. “The resignation of Egyptian President Hosni Mubarak is the beginning of the victory of the Egyptian revolution,” he said. “Such a victory was the result of the sacrifices and the steadfastness of the Egyptian people.” Amr Moussa, the secretary general of the Arab league and himself an Egyptian, described the popular revolt as a “white revolution” that would provide an opportunity. He said he would work to help build national consensus in his homeland. Within the wider Arab world, the royal council of the Emir of Qatar called the resignation “a positive, important step towards the Egyptian people's aspirations of achieving democracy and reform and a life of dignity”.