Hegseth says more US forces arriving in Middle East as Iran war ramps up 

US Defense Secretary Pete Hegseth has said more United States forces are arriving in the Middle East, as the country’s war against Iran intensifies amid mounting concerns over the civilian toll of US-Israeli strikes.

Hegseth said during a news conference at the Pentagon on Wednesday that the US-Israeli campaign against Iran was “just getting started”.

“We are accelerating, not decelerating … More bombers and more fighters are arriving just today,” he told reporters, adding that the US would be using a “nearly unlimited” supply of 226kg (500lb), 453kg (1,000lb) and 900kg (2,000lb) bombs.

The US and Israel, he said, would sow “death and destruction from the sky, all day long”.

Hegseth’s combative remarks come five days into the US-Israel war against Iran, which has killed at least 1,045 people across the country since Saturday, according to Iran’s semiofficial Tasnim news agency.

Legal experts have slammed the offensive as a violation of the United Nations Charter as well as a breach of international law, while humanitarian groups have raised alarm over the war’s effects on civilians in the Middle East.

Reporting from the Iranian capital Tehran, Al Jazeera’s Mohamed Vall said civilians “are bearing the brunt” of US-Israeli attacks.

“[The] strikes are continuous,” he said on Wednesday evening, noting that three-quarters of Tehran’s residents have reportedly left the city.

“The authorities here are accusing the Americans and the Israelis of chaotic strikes against the country, [and a] lack of precision and lack of clarity of targets in this campaign.”

Tehran’s response to the attacks also has drawn condemnation, as the country has fired missiles and drones across the region, killing at least six US service members and 11 people in Israel.

The Iranian firings have increasingly targeted oil and gas infrastructure in the Gulf, prompting concerns about disruptions to global energy markets.

In a statement on Wednesday, the Norwegian Refugee Council (NRC) warned that the war was having a “stark” impact on civilians across the Middle East.

“This deadly escalation is compounding the suffering of people already hurt or impoverished by previous rounds of conflict,” said Jan Egeland, the humanitarian group’s secretary-general.

“We call on all parties to de-escalate, protect civilians and civilian infrastructure, including schools and hospitals, respect their obligations under international humanitarian law, and allow safe and unhindered humanitarian access. The people of this region have endured enough.”