David Miliband said too many people had died in the conflict
UK Foreign Secretary David Miliband has welcomed Israel's decision to declare a unilateral ceasefire in Gaza.
Describing Israeli Prime Minister Ehud Olmert's announcement as a "huge relief", he said the 22-day conflict had already claimed too many lives.
Mr Miliband said the country had listened to international pressure and it was now "imperative" for Hamas to stop its rocket attacks on Israel.
Earlier, Gordon Brown offered UK naval resources to help monitor the conflict.
In a statement, Mr Miliband said: "There will be huge relief at the announcement by Prime Minister Olmert of the end of Israeli military operations in Gaza.
"Too many lives have already been lost. The deaths of over 1,000 people stand testament to the scale and duration of the conflict.
"The voice of the international community has been loud and unequivocal in calling for an immediate, permanent and fully respected ceasefire.
"It is now imperative that Hamas stops the rocket attacks against Israeli civilians."
The foreign secretary called for the Gaza strip to be opened up to aid workers as quickly as possible.
"We now need to see the UN and the other aid agencies allowed immediate access into the Gaza strip and a guarantee of their safety so they may do their vital work unhindered," he said.
The call came as it emerged that Mr Brown is considering an invitation to attend an international summit on Sunday in Egypt about the conflict.
Earlier the prime minister offered the UK resources in a bid to help ensure protection and monitoring of the crossings into Gaza.
Mr Brown said: "We will do everything we can to prevent the arms trading at the root of the problems."
Mr Olmert said Israel's operation in Gaza had fully achieved its aims, with Hamas badly damaged militarily and in terms of infrastructure.
Earlier a Hamas spokesman said it would fight until its demands were met, including an Israeli withdrawal.
Shadow defence secretary Liam Fox criticised the prime minister's offer of naval resources, saying Mr Brown could not commit "our already over-stretched forces to more and more missions while reducing their resources".
Mr Brown's announcement followed an agreement signed between the US and Israel on Friday.
The deal called for expanded intelligence co-operation to prevent Hamas smuggling weapons into the Gaza Strip.
Israel has accused Hamas of using tunnels between Gaza and Egypt to smuggle arms. The Egyptian government has said the tunnels are mainly used for food.