The Kremlin on Tuesday conceded that Russia would not reach its 60 percent vaccination target by the end of summer as the country registered its highest daily death toll.

Russia has grappled with a recent spike in infections spurred by the highly contagious Delta variant while struggling to get its citizens inoculated.

An official government tally reported 652 coronavirus fatalities in the country over the past 24 hours, topping a record that was set in December last year. 

A record-high number of daily deaths -- 119 -- was also reported in Russia's second city Saint Petersburg, which is due to host a Euro 2020 quarterfinal on Friday.

Some experts say that Russia vastly underreports coronavirus fatalities, counting only cases when Covid-19 was found to be the primary cause of death after autopsy.

Over the past few weeks, Saint Petersburg and the capital Moscow have seen a spike in infections, with authorities re-introducing virus restrictions and moving to boost a sluggish vaccination drive. 

Despite free jabs having been available since December, just 22.2 million out of a population of about 146 million had received at least one dose as of Monday, according to the Gogov website, which tallies Covid figures from the regions and the media.

Kremlin spokesman Dmitry Peskov said on Tuesday that Russia would be adjusting its current vaccination target. 

"Only this week the number of those wishing to get vaccinated has more or less started growing," Peskov told reporters.

"Obviously it will not be possible to vaccinate 60 percent of the population" by the autumn, he said.

Mandatory jabs 

Moscow Mayor Sergei Sobyanin had said that the more contagious Delta variant first identified in India accounts for 90 percent of cases in the capital. 

To curb the spread of infections, the mayor ordered Moscow businesses to send home 30 percent of unvaccinated employees and restaurants to only allow inside patrons who have been inoculated or infected in the past six months.

Moscow also became the first Russian city to introduce mandatory vaccinations, requiring at least 60 percent of service industry workers to be fully inoculated by mid-August.

At least a dozen Russian regions followed suit, requiring certain groups of citizens to get one of Russia's jabs. Polls show that the population remains sceptical of homegrown vaccines.

The Kremlin maintains that vaccination in Russia is voluntary.

Nationwide, infections grew by 20,616, bringing Russia's caseload to nearly 5.5 million -- the fifth-highest worldwide, according to an AFP tally. 

With 134,545 deaths from the virus, Russia has the highest toll from Covid-19 in Europe -- even as authorities have been accused of downplaying the severity of the country's outbreak.

Under a broader definition for deaths linked to coronavirus, statistics agency Rosstat at the end of April said that Russia has seen at least 270,000 fatalities.