Mr Brown, along with the leaders of France, Germany and Italy, said he was offering military and humanitarian help to implement a cease-fire and ease the suffering in Gaza, where hundreds have died since Israel began its offensive in the territory in late December.
'The Israelis, Egyptians and Palestinian Authority know this offer is available,' Mr Brown said. 'I think this may make it easier for people to come to a cease-fire.' Israel's leaders voted late on Saturday to halt an offensive aimed a delivering a crushing blow to Islamic militant group Hamas, which has bombarded southern Israel with rockets from its power base in Gaza.
British Foreign Secretary David Miliband said there would be 'huge relief' at the announcement. He called on Hamas to end its rocket attacks and on Israeli authorities to allow aid agencies immediate access to Gaza and a guarantee of their safety.
'Too many lives have already been lost,' Mr Miliband said in a statement released late on Saturday. Earlier, Mr Brown had suggested that Britain could help move injured children out of Gaza so they could receive medical care elsewhere.
The prime minister said Britain could also help remove unexploded bombs in the Gaza area and would be prepared to increase the level of its humanitarian aid over the next five years.
Mr Brown was due in Egypt on Sunday for a summit aimed at giving international backing to the cease-fire. It is also to be attended by the leaders of Germany, France, Spain, Italy, Turkey and the Czech Republic - which holds the rotating EU presidency - as well as Palestinian President Mahmoud Abbas, Egyptian leader Hosni Mubarak and UN chief Ban Ki-moon.
In Germany, Chancellor Angela Merkel's office released a statement saying that the European leaders all expressed support for 'the efforts of the Israeli and Egyptian governments to reach a lasting cease-fire in Gaza'.
There were continued protests against the Israeli military action Saturday in London and several other British cities. Protests turned violent late on Saturday when demonstrators broke into stores in the center of London, smashing windows and looting merchandise, according to police.
Earlier on Saturday morning, a group of activists broke into a weapons factory in the southern English city of Brighton, damaging machinery and causing what authorities said were substantial losses. The group claimed that the EDO MBM Technology Ltd. plant they raided was manufacturing equipment being used in Gaza by the Israeli air force.