MOSCOW- President Vladimir Putin warned on Monday that the coronavirus situation in some Russian regions was getting worse as authorities began promoting the idea of regular revaccinations to try to halt a surge in new cases.

Putin this month spoke of how Russia, which has approved four domestically-made vaccines and sold its flagship Sputnik V vaccine to many foreign countries, had handled the pandemic better than many other nations.

But new cases have since surged, particularly in Moscow, which on Saturday registered a record 9,120 daily cases. The Kremlin on Friday blamed the increase on people's reluctance to have vaccinations and "nihilism". 

"Unfortunately, the coronavirus threat has not receded," Putin told the lower house of parliament on Monday. "In many regions the situation has even got worse."

Grim video footage emerged on social media on Sunday, purportedly showing people sick with COVID-19 laying prone on the floor of a hospital corridor in St Petersburg, Putin's home city which is hosting some matches in the Euro 2020 soccer championship.

Local authorities are investigating the video to check its veracity.

The authorities are trying to coax and compel people to get vaccinated, offering those who do the chance to win new cars and flats, while threatening others who don't with loss of earnings and dismissal. 

The authorities have blamed the surge, which has seen more than 17,000 new COVID-19 cases reported for a fourth day running, on the new Delta variant, while conceding that a nationwide ad campaign meant to encourage people to get vaccinated had fallen short.

It's too early to say if the surge will prove a political headache for the Kremlin which faces parliamentary elections in September. Vaccines have been widely available for months but many Russians have been reluctant.

By June 2 only 18 million of the around 144-million-strong population had received at least one dose of a vaccine. 

The Kremlin has denied people's distrust in the authorities is one of the reasons behind the low vaccination rate.

Critics on social media have said state media's take down of some foreign vaccines has added to people's fears about getting vaccinated however, and have complained that some senior officials set a poor example, taking a long time to get vaccinated themselves and then only doing so behind a veil of secrecy.

Kremlin spokesman Dmitry Peskov told reporters on Monday that revaccinations were the way forward.

"Revaccination will be and is inevitable - not just vaccination, but revaccination - for those who want to keep themselves, their relatives and loved ones safe," said Peskov.

Russia reported 17,378 new COVID-19 cases on Monday and 440 deaths linked to coronavirus in the last 24 hours.

(Reporting by Gleb Stolyarov and Alexander Marrow; Editing by Andrew Osborn) ((alexander.marrow@thomsonreuters.com;))