French President Emmanuel Macron refused a Kremlin request that he take a Russian COVID-19 test when he arrived to see President Vladimir Putin this week, and was therefore kept at a distance from the Russian leader, two sources in Macron's entourage told Reuters.

Observers were struck by images of Macron and Putin sitting at opposite ends of 4-metre-long (13 ft) table to discuss the Ukraine crisis on Monday, with some diplomats and others suggesting Putin might be wanting to send a diplomatic message.

But the two sources, who have knowledge of the French president's health protocol, told Reuters Macron had been given a choice: either he accepted a PCR test done by the Russian authorities and was allowed to get close to Putin, or he refused and had to abide by more stringent social distancing.

"We knew very well that meant no handshake and that long table. But we could not accept that they get their hands on the president's DNA," one of the sources told Reuters, referring to security concerns if the French leader was tested by Russian doctors.

A Kremlin spokesman did not immediately respond to a message from Reuters seeking comment.

The second source in Macron's entourage confirmed Macron declined to take a Russian PCR test. The source said Macron instead took a French PCR test before departure and an antigen test done by his own doctor once in Russia.

"The Russians told us Putin needed to be kept in a strict health bubble," the second source said.

On Thursday, three days after Macron and Putin had their socially-distanced meeting, the Russian leader received Kazakh President Kassym-Jomart Tokayev. The two men shook hands, and sat close to each other, divided only by a small coffee table.