Russia will see a sharp rise in the mortality figures for May, officials said Friday, as the coronavirus death toll rises.

"There will be a significant mortality increase in May" Deputy Prime Minister Tatiana Golikova said at a government meeting with President Vladimir Putin, referring to official analysis and the country's coronavirus curve.

"The illness and chronic conditions don't always have a positive ending," Golikova said, despite doctors trying to "save the maximum number of patients."

Moscow Mayor Sergei Sobyanin also said the capital's death figures for May will be "considerably higher than in April."

Russia registered 150 deaths from the coronavirus on Friday, its highest daily rate yet, amid criticism that the authorities are under-reporting the virus fatalities to play down the scale of the crisis.

Health officials have reported a total of 3,249 virus-related deaths, a fraction of the number in some European countries, while Russia has the second-highest number of infections in the world, after the United States, with 326,448 cases.

Other countries with lower numbers of cases and more modern health systems, such as Italy, have reported ten times the number of deaths.

Russian officials said fatalities will rise in May due to the number of gravely ill patients in hospital.

Around 109,000 people are currently hospitalised, with some 2,500 of those in intensive care, Health Minister Mikhail Murashko said Friday. The number in hospital has increased from around 80,000 on May 6.

"The number of deaths from the coronavirus will be higher in May than in April, because the virus peak was at the beginning of May," Sobyanin said.

"The seriously ill are building up. Doctors try to save each one who lies there for two, three or more weeks... unfortunately it's not possible to save them all."

Golikova said that around four percent of the current cases are in a grave condition, or around nine thousand people.