The British foreign secretary has denounced the "utterly horrifying” and “wholly preventable" famine in Gaza, saying Israel's refusal to allow sufficient aid has caused this "man-made catastrophe".

In a statement on Thursday, David Lammy reiterated his criticism over the humanitarian situation in Gaza after the UN-backed Integrated Food Security Phase Classification (IPC) report declared famine in the Gaza Governorate.

“The Israeli government’s refusal to allow sufficient aid into Gaza has caused this man-made catastrophe. This is a moral outrage," he said.

"The Government of Israel can and must immediately act to stop the situation from deteriorating any further," Lammy said and urged Israel to immediately and sustainably allow unhindered food, medical supplies, fuel, and all types of aid to reach those who so desperately need them.

Recalling his call for an immediate ceasefire, the foreign secretary said Israel's military operation in Gaza City is the epicentre of the famine.

"The UK reiterates its condemnation of this military action, which will only worsen the already catastrophic humanitarian situation and endanger the lives of the hostages held by Hamas," said Lammy.

He urged Israel to change course and halt its plans to occupy Gaza City.