The theft of vaccines is particularly serious, after the International Committee of the Red Cross said there were now one million cases of cholera in Yemen and they expect another serious outbreak next March and April.
Yemen, one of the Arab world's poorest countries, is in a proxy war between the Iran-allied Houthi armed movement and a USA -backed military coalition headed by Saudi Arabia.
In turn, the United Nations noted that the situation in Yemen is one of the most serious humanitarian crises in the world.
The ICRC said that to have reached one million cases in such a short time is "a ugly milestone in the 21st century".
Health workers in Yemen have decried an acute shortage of medicine supplies amid an unfolding Cholera outbreak in the war-torn country.
A new wave of cholera is expected in March or April.
It's probably unavoidable. We need to be ready to face another big epidemic.The places where the war is active are the ones most at risk for increase of disease.More news: Bomb squad responds to manure-filled package sent to Mnuchin's LA home
Marc Poncin, the emergency coordinator for Doctors Without Borders (MSF) in Yemen , told AFP that cholera mortality rates had been on a downtrend in recent months but that the disease was far from vanquished.
Diphtheria, a potentially fatal contagious bacterial infection, has also emerged as a major health threat in the impoverished country. More than 12,000 have died since the war began.
The disease, which has not been seen in Yemen for 25 years, has affected 312 people and killed 35. The cholera outbreak has wiped out the wreckage of what once the Yemeni healthcare system.
President Donald Trump succeeded at getting Saudi Arabia to end its blockade of goods to Yemen, which is facing a humanitarian crisis due to a lack of supplies.
Deputy Assistant Secretary of State Tim Lenderking said the United States would have a conversation with Saudi Arabia about 30 days the port will be open and about possibly changing the timeline, but said the US first wants to see ships moving in and goods and services reaching the people of Yemen.
Ambassador to Riyadh Adnan Alonto reported on Tuesday the successful interception by Saudi authorities of a ballistic missile launched from Yemen that targeted a populated area in Riyadh.