Russian President Vladimir Putin on Wednesday criticised delays in the construction of a new cosmodrome in the country's far east, which has been plagued by corruption and strikes over unpaid wages.

Russia is building the new Vostochny Cosmodrome to reduce its dependence on the Baikonur launch site that it rents in neighbouring Kazakhstan.

Construction of the cosmodrome -- which will be used for satellite and manned launches -- has become bogged down in alleged corruption, with those in charge under investigation.

His remarks were made after meeting Deputy Prime Minister Dmitry Rogozin, a close ally who is responsible for the space industry and who told him the project was still around four months behind schedule.

It had previously been lagging by eight months.

"This is still a big delay," Putin said as he visited the construction site, in comments published on the Kremlin website.

"I stress again we must aim to observe the set plans on bringing the cosmodrome into operation while, of course, not resorting to a rush job," he said.

Putin also called for the Russian space agency and those involved in the construction to present a report on the delays.

The project has cost around 188 billion rubles ($3 billion/2.6 billion euros) of state money.

The first unmanned launch from the site is planned for December 2015 and Rogozin said he would make every effort to ensure it happened.

But Putin warned against a "last-minute rush."

"Aim for the first launches in 2016, some time in spring," he said.

The space base was originally set to start hosting manned space launches from 2018, but this will now be put back to 2025.

Russia has an existing military launch base Plesetsk in the far north, which is used for satellite launches and testing missiles.

Like the Baikonur site in Kazakhstan, the new cosmodrome is closer to the equator which will make launches more energy-efficient and hence cheaper.