Dr. Maria Van Kerkhove, WHO infectious disease epidemiologist, said there had been "misunderstandings" about her comments made on Monday.
In a Facebook Live video, Van Kerkhove said asymptomatic people can in fact spread the virus, though the degree to which they can is unknown.
"We do know that some people who are asymptomatic or some people who don't have symptoms can transmit the virus on," she said. "What we need to better understand is how many people in the population don't have symptoms and, separately, how many of those individuals go on to transmit to others."
She said she was referring to two or three studies when she made her statement on Monday.
"In that I used the phrase 'very rare,' and I think that's a misunderstanding to state that asymptomatic transmission globally is very rare," she said. "What I was referring to is a subset of studies."
Some modeling groups estimate about 40 percent of virus transmission may be due to asymptomatic people, she said. Van Kerkhove did not include that figure on Monday but wanted to make sure she included it in her clarification.
Experts and members of the public, like Andy Slavitt, former health official under the Obama administration, voiced frustrations at the miscommunication over social media.