The world is already seeing a resurgence of COVID-19 cases and deaths in some countries after many governments embarked on reopening economies, the World Health Organization's Director-General Tedros Adhanom said on Friday.

Tedros was speaking at a media briefing on the COVID-19 situation and progress of response.

"As some countries start to open up we see cases and deaths starting to spike and concerns about potential lack of hospital capacity," he said. "This is a critical moment for countries and we ask leaders to put targeted measures in place that we know can suppress the spread and ensure that health systems and workers are protected."

The WHO chief reiterated calls for adherence to health protocols in efforts to curb further spread of the virus.

"We ask you to continue to do the basics. Physical distancing, hand washing, mask wearing, coughing and sneezing safely away from others, avoiding crowds and keeping windows and doors open when you can't meet friends and family outside," he said.

Tedros' remarks came as the number of COVID-19 infections globally surpassed the 30.24 million mark, with a death toll exceeding 947,000, according to figures from the U.S.-based Johns Hopkins University.