DUBAI - The United States is already heavily involved in the conflict between Israel and Hamas and must be held to account, an Iranian official said on Monday.

The US is bolstering its firepower in the Middle East in response to war between its ally Israel and the Iranian-backed Palestinian militants Hamas amid fears of regional spillover.

Asked if Teheran would engage if the US weighed in, Foreign Ministry spokesperson Nasser Kanaani said: "Iran considers that the United States is already militarily involved in the conflict between Israel and Palestinians."

"The crimes of the Zionist regime are carried out with the support of the United States and Washington must be held accountable," he added at a news conference.

The newest US aircraft carrier - also the world's largest - is already in the eastern Mediterranean and is due to be joined by a second US aircraft carrier in coming days.

US Secretary of State Antony Blinken said on Sunday the aircraft carriers are not a provocation but a deterrence. REUTERS