(CNN) -- World Health Organization officials warned during a news briefing in Geneva on Wednesday that globally there is a "significant shortage" of medical supplies, including personal protective gear or PPE.

This issue is something that officials said WHO Director-General Tedros Adhanom Ghebreyesus will be bringing up at the G20 summit on Thursday.

"We need to be clear: The world is facing a significant shortage of PPE for our frontline workers — including masks and gloves and gowns and face shields — and protecting our health care workers must be the top priority for use of this PPE," Dr. Maria Van Kerkhove, WHO infectious disease epidemiologist, said during Wednesday's briefing.

All elements of the supply chain appear to be under "extreme strain," Dr. Mike Ryan, WHO executive director of the health emergencies program, said during the briefing.

"There are problems in the supply chain all along that chain. The simple issue is demand," Ryan said. "There are shortages of PPE, shortages of ventilators and other products for the medical response to Covid. We also have to avoid shortages in other medical supplies, as supply chains come under strain."