(AFP) - The World Health Organization's executive board on Sunday adopted a resolution calling for immediate, unimpeded humanitarian access to Gaza after the WHO chief said medics were facing unimaginable conditions.

The 34 countries on the board adopted the resolution by consensus, even though some, notably the United States, had reservations about the dearth of references to the Hamas attacks of October 7.

In addition to calling for immediate humanitarian relief, the resolution demanded the granting of exit permits for patients.

WHO chief Tedros Adhanom Ghebreyesus said the board had managed to achieve "the first consensus resolution on the conflict... since it began two months ago."

He added it was "a platform on which to build".

The resolution seeks the supply and replenishment of medicine and medical equipment to the civilian population and ensure access to medical treatment.

It was brought forward by Afghanistan, Morocco, Qatar and Yemen.

US ambassador Bathsheba Crocker said Washington agreed not to block consensus on the text but had "significant reservations", saying it "regrets the lack of balance in the resolution".

Canada said it considered the text a "compromise resolution" which could have gone further with additional language acknowledging the role of Hamas in the conflict, its taking of hostages and "use of human shields".

And Australia took issue with the text not making specific reference to the October 7 attacks which it said has been "the catalyst for the current devastating situation".

- 'On its knees' -

Tedros opened the special session in Geneva by saying the war between Israel and Hamas was having a "catastrophic impact" on health in Gaza, with medics facing an "impossible" job.

"As more and more people move to a smaller and smaller area, overcrowding, combined with the lack of adequate food, water, shelter and sanitation, are creating the ideal conditions for disease to spread," he said.

"Gaza's health system is on its knees and collapsing," Tedros said, with only 14 out of 36 hospitals functioning with any capacity at all. Only 1,400 hospital beds out of an original 3,500 are still available, he added.

Israel has vowed to eradicate Hamas after the group's unprecedented attacks on October 7, when its fighters broke through Gaza's militarised border, killed about 1,200 people and seized hostages, according to Israeli officials.

In response, Israel's military offensive in Gaza has killed almost 18,000 people, mostly women and children, according to the Hamas-run health ministry.

- 'Daily horrors' -

The special session was called by 17 of the 34 countries on the executive board, which advises the WHO's decision-making body, and then implement its decisions.

Palestinian health minister Mai al-Kaila, speaking via video-link from Ramallah, called for the immediate cessation of the "brutal war in Gaza" and the unconditional flow of fuel, water, aid and medical supplies into the territory.

"The daily horrors we all witness defy international law and shatter the very essence of our shared humanity," she said.

Meirav Eilon Shahar, Israel's ambassador in Geneva, said that on October 6, "there was a ceasefire with Hamas. On October 7, we woke up to a new reality".

"Hamas is responsible for this suffering" she said, adding: "If we stop now, Hamas will carry out another October 7."

© Agence France-Presse