(Corrects headline and first paragraph to show leaders threatened concrete actions over Gaza, not sanctions)

LONDON (Reuters) -The leaders of Britain, Canada and France threatened "concrete actions" against Israel on Monday if it does not stop a renewed military offensive in Gaza and lift aid restrictions, piling further pressure on Prime Minister Benjamin Netanyahu.

The Israeli military announced the start of a new operation on Friday, and earlier on Monday Netanyahu said Israel would take control of the whole of Gaza. International experts already have warned of looming famine.

"The Israeli Government's denial of essential humanitarian assistance to the civilian population is unacceptable and risks breaching International Humanitarian Law," a joint statement released by the British government said.  

"We oppose any attempt to expand settlements in the West Bank ... We will not hesitate to take further action, including targeted sanctions."   

In response, Netanyahu said that "the leaders in London, Ottawa and Paris are offering a huge prize for the genocidal attack on Israel on October 7 while inviting more such atrocities".

He said Israel will defend itself by just means until total victory is achieved, reiterating Israel's conditions to end the war which include the release of the remaining hostages and the demilitarization of the Gaza strip.

Israel has blocked the entry of medical, food and fuel supplies into Gaza since the start of March to try to pressure Hamas into freeing the hostages the Palestinian militant group took on October 7, 2023, when it attacked Israeli communities.  

"We have always supported Israel's right to defend Israelis against terrorism. But this escalation is wholly disproportionate," the three Western leaders said in the joint statement. They said they would not stand by while Netanyahu's government pursued "these egregious actions."

They stated their support for efforts led by the United States, Qatar and Egypt for an immediate ceasefire in Gaza, and said they were committed to recognising a Palestinian state as part of a two-state solution to the conflict.

Hamas welcomed the joint statement describing the stance as "an important step" in the right direction toward restoring the principles of international law.

    Israel's ground and air war has devastated Gaza, displacing nearly all its residents and killing more than 53,000 people, many of them civilians, according to Gaza health authorities.

The war began with the October 7, 2023, Hamas-led attack in which the militants killed about 1,200 people, mostly civilians, and seized 251 hostages, according to Israeli tallies.

(Reporting by Muvija M; Editing by Andrew Cawthorne, Sandra Maler and Howard Goller)