The World Health Organisation (WHO) has suspended the trials of hydroxychloroquine — the malaria drug U.S. President Donald Trump says he is taking — from its global study into experimental COVID-19 treatments, saying that its experts need to review all available evidence to date.

The announcement was made by WHO Director-General Dr. Tedros Adhanom Ghebreyesus. "The executive group has implemented a temporary pause of the hydroxychloroquine arm within the Solidarity trial while the safety data is reviewed by the data safety monitoring board. The other arms of the trial are continuing," Tedros told an online briefing.

"This concern relates to the use of hydroxychloroquine and chloroquine in COVID-19," Tedros said, adding that the drugs are approved treatments for people with malaria or autoimmune diseases. Other treatments in the trial, including the experimental drug remdesivir and an HIV combination therapy, are still being tested.