The State Department is vouching for photographic "evidence" that purports to show Russian special forces in eastern Ukraine, despite Vladimir Putin's claims that his operatives are not behind the unrest.
Ukraine's government has been circulating images over the last several days to international organizations, claiming they show "Russian sabotage-reconnaissance groups" at work in two eastern Ukrainian towns.
Their authenticity could not be independently verified, but State Department spokeswoman Jen Psaki said Monday they help bolster claims of ties between Russia and armed militants in eastern Ukraine.
"So these are just further evidence of the connection between Russia and the armed militants," she said.
Psaki repeatedly described the images that way when pressed for more information at Monday's press briefing. She said they show "individuals who visibly appear to be tied to Russia."
The photos were circulating on the heels of a diplomatic agreement in Geneva meant to ease tensions in Ukraine's eastern region. Following a deadly shooting on Sunday, the White House would not say Monday when pro-Russian militants must lay down their arms.
The images, and the captions, purport to show a select group of militants photographed during earlier pro-Russian operations, and again during operations in Kramatorsk and Sloviansk, in eastern Ukraine.
One set shows a bearded man in a military cap in several settings. The captions claim one image was taken in Georgia in 2008, and two others were taken in Kramatorsk and Sloviansk this year. They appear to show the same person. The document labels him as a "soldier of the Russian Special Forces."
Another set purports to show another militant in eastern Ukraine, and in a "family photo" of a Russian forces group.
The photos were included in a letter sent by Ihor Prokopchuk, Ukraine's permanent representative to the International Organizations in Vienna, to delegations of the Organization for Security and Co-operation in Europe.
The New York Times initially reported on these photographs, saying they show militants in eastern Ukraine equipped in the "same fashion" as Russian forces.
Putin, though, has denied his forces are in eastern Ukraine.
Fox News' Lucas Tomlinson and The Associated Press contributed to this report.