Gunmen from the Palestinian Islamist group Hamas stormed across Gaza's border with Israel on October 7, killing about 1,400 people, mostly civilians, and taking over 240 hostages, according to Israeli officials.

Since then, Israel has relentlessly bombarded Gaza and sent in ground troops, with the health ministry in the Hamas-run territory saying more than 9,700 people have been killed, also mainly civilians.

"The aid from the United States to the Zionist regime (Israel) is encouraging them to kill and commit cruel acts of neglect against the Palestinian people," Raisi said at a joint news conference in Tehran with visiting Iraqi Prime Minister Mohammed Shia al-Sudani.

"We believe that the bombings must stop as soon as possible, that a ceasefire must be declared immediately and that aid be provided to the oppressed and proud people of Gaza," Raisi said.

"These horrible crimes against humanity are a genocide, which is carried out by the Zionist regime (Israel) with the support of the United States and certain European countries."

The Iraqi leader's visit to Iran comes a day after US Secretary of State Antony Blinken made a surprise stop in Baghdad on his diplomatic tour of the Middle East to meet with Sudani.

In Baghdad, Blinken slammed "attacks or threats" against US troops in Iraq and Syria by militias that the United States says have ties to Iran.

Since the start of the Hamas-Israel war, rocket and drone attacks have targeted military bases hosting US forces in Iraq.

Iraq is close to Iran, and neither Baghdad nor Tehran recognises the state of Israel.

On October 25, Iran's supreme leader Ayatollah Ali Khamenei described the United States of being "the undeniable accomplices of the crimes" perpetrated in Gaza.

Iran financially and militarily backs Hamas but insists it had no involvement in the Palestinian Islamist group's October 7 attacks on Israel, the worst in the country's 75-year history.