Fox News medical contributor Dr. Marc Siegel told "Tucker Carlson Tonight" Tuesday that the latest reversal from the World Health Organization has left him wondering, "How can we possibly trust the WHO at all?"

"Yesterday, when I heard their head of emerging diseases [Dr. Maria Van Kerkhove], [who] trained at the London school of [Hygiene &] Tropical Medicine as a top epidemiologist, I thought 'I’m going to give her the benefit of the doubt,'" Siegel said. "She is saying asymptomatic spread is very rare and I thought 'Finally, a shining star coming out of the WHO I can hang my hat on.'"

WHO OFFICIAL WALKS BACK STATEMENT THAT ASYMPTOMATIC TRANSMISSION IS 'VERY RARE'

"Guess what?" he continued. "Today, she walked the whole thing back and ... I know I’m left thinking how can we possibly trust the WHO at all?"

Van Kerkhove said earlier Tuesday that there had been "misunderstandings" about comments she made Monday, when she stated that coronavirus transmission by asymptomatic individuals was “very rare.”

The WHO's Maria Van Kerkhove attending a virtual news briefing on COVID-19 in April. (AFP via Getty Images)

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 need our testing, we need officials to be honest with us, [and] we need to know the real science here," Siegel said. "We don’t need anybody jumping to false conclusions and misleading us any further about COVID-19."

Fox News' Kayla Riva contributed to this report.