The World Health Organization (WHO) has stopped a clinical trial for hydroxychloroquine, a malaria drug US President Donald Trump said he was taking, in Covid-19 patients amid safety concerns, Deutsche Welle reports.

A paper in the Lancet, a peer-reviewed medical journal, showed that people taking the drug were at higher risk of death and heart problems than those that were not.

"This concern relates to the use of hydroxychloroquine and chloroquine in Covid-19," WHO director-general Tedros Adhanom Ghebreyesus told a news briefing.

Dr. Mike Ryan, who heads the WHO emergency program, said the decision to suspend the trial was taken out of "an abundance of caution." The organization will pursue other treatments as part of its study, including the experimental drug remdesivir and an HIV combination therapy.

Last week, Trump told a news conference he was taking hydroxychloroquine every day for two weeks to ward off the new coronavirus.