Praise for the way U.S. agencies secured and shared intelligence on Russia's plans to invade Ukraine are being tempered by growing concern that one of the Kremlin's disinformation campaigns is starting to take hold in the United States and the West.
For days, officials at the White House, State Department and Pentagon have been pushing back against Moscow's claims — increasingly repeated by far-right and far-left social media channels, as well as by some mainstream media in the United States — that Russian forces have found, and in some cases destroyed, Ukrainian biological weapons labs funded by the U.S.
"I'm fearful that this could be the new direction of a Russian false flag operation," Senate Intelligence Committee Chairman Mark Warner, a Democrat, told top U.S. intelligence officials at a hearing Thursday.
The committee's ranking Republican, Senator Marco Rubio, said the Russian accusation, combined with recent comments by some U.S. officials, have "got some people fired up."
U.S. intelligence officials echoed their concerns, noting that while there are more than a dozen so-called biolabs in Ukraine, their work is focused on understanding and preventing pandemics and the spread of infectious disease, and nothing more.
"Let me be clear. We do not assess that Ukraine is pursuing either biological weapons or nuclear weapons ... the propaganda that Russia is putting out," Director of National Intelligence Avril Haines told the lawmakers.
Haines said that while Washington has in the past provided some assistance, it has been in the context of biosafety, and mirrors U.S. outreach to other countries that have similar medical research facilities.
"This influence campaign is completely consistent with long-standing Russian efforts to accuse the United States of sponsoring bioweapons work in the former Soviet Union," Haines added.
The U.S. spy chief was equally blunt.
"Unlike Russia, which does have chemical weapons and has used them and has done biological research and has for years, Ukraine has neither," Central Intelligence Agency Director William Burns told the Senate panel.
The threat from biological research facilities, like the ones in Ukraine, "is in no way akin to the kind of threats that would be posed by weapons research and development," Burns said.
Instead, Burns raised concern that Russia might be telegraphing one of its next moves in its now two-week-old invasion of Ukraine.
"This is something ... that's very much a part of Russia's playbook," he said. "They've used those weapons against their own citizens. They've at least encouraged the use in Syria and elsewhere, so it's something that we take very seriously."
Rumors about supposed U.S.-backed Ukrainian bioweapons facilities first began popping up months ago but appear to have started to gain traction among some U.S. and Western audiences in late February.
"You're asking me about bioweapons sites in labs in Ukraine, and by my count there are more than 20," Joe Oltmann, the co-host the Conservative Daily Podcast, told VOA this past Monday, after having debated the charge on his show the previous week.
"I promise you that the U.S. Department of Defense did not give somebody money for drywall to renovate it or couches," he said.
Talk about such facilities seemed to gain additional momentum on Tuesday, after Rubio asked about the labs during a hearing by the Senate Foreign Relations Committee.
"Ukraine has biological research facilities, which, in fact, we are now quite concerned Russian troops, Russian forces may be seeking to gain control of," replied Undersecretary of State Victoria Nuland.
"We are working with the Ukrainians on how they can prevent any of those research materials from falling into the hands of Russian forces should they approach," she added.
Russian accounts and Russian-affiliated media seized on the comments, taking to social media to reinforce the narrative.
"The information received from various sources confirms the leading role of the U.S. Defense Threat Reduction Agency in financing and conducting military biological research on the territory of Ukraine," Russia's Ministry of Defense posted on its English-language Telegram channel Thursday.
"It is highly likely that one of the objectives of the U.S. and its allies is to create bioagents capable of selectively targeting different ethnic populations," the Russian ministry added.
The Pentagon on Wednesday rejected the allegations by Russia and others, calling them "absurd."
"In the words of my Irish Catholic grandfather, it's a bunch of malarkey," Pentagon press secretary John Kirby told reporters. "We are not, not developing biological or chemical weapons inside Ukraine."
U.S. intelligence officials Thursday told lawmakers that contrary to the Kremlin's accusations, the real danger from the labs comes if or when Russian troops capture the facilities.
The medical research labs "all have equipment or pathogens or other things that you have to have restrictions around because you want to make sure that they're being treated and handled appropriately," Haines said. "We have to be concerned the same way we have to be concerned about a nuclear power plant."