President Vladimir Putin on Thursday gave a dressing down to space officials on a visit to Russia's long-delayed and corruption-tainted cosmodrome in the Far East.
The Vostochny cosmodrome was originally supposed to be running manned launches from last year but the grand project has been consistently behind schedule.
At a meeting with the head of the country's space agency Dmitry Rogozin and others, Putin asked for details on how close the spaceport is to completion.
"I expect a more responsible attitude from you and a dynamic pace when organising work," Putin said in televised comments.
"All the infrastructure being built on the ground here must meet the latest demands and standards to ensure launches of our advanced rocket systems," the president said.
The cosmodrome in the Amur region is one of Russia's most important space projects, designed to reduce its reliance on the Baikonur launch site it rents from Kazakhstan to ferry astronauts.
State television hailed it as "the country's main construction site". Russia hopes the facility will restore its Soviet-era supremacy.
While five unmanned launches have already taken place from the cosmodrome, "Vostochny's capacities can -- and I want to stress, should -- be used more seriously," Putin warned.
Ahead of the visit, Putin said he was going because "there are a lot of questions there needing a solution and needing my intervention in this process."
On Friday, Putin visited accompanied by deputy prime minister Yury Borisov who last week sharply criticised the project and suggested bringing in the army to finish the job.
Often outspoken space agency chief Rogozin responded on Twitter: "That's always the way: some are building, others are criticising."
On Friday Rogozin told news agencies: "We have no reason to change the contractor. We are working to schedule."
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The budget for Vostochny's construction was estimated at 300-400 billion rubles ($4.5 billion to $6 billion at the current exchange rate).
The space port was set to open in December 2015, with the first manned launch in 2018.
Last year, Russia jailed four who were working as contractors on the construction for embezzling state funding worth some $23 million.
There were also scandals over unpaid wages to workers.
The cosmodrome has a completed launch pad for Soyuz rockets, meaning it can be used for manned flights in the future.
Putin viewed the project's unfinished second phase, on which work only began in April. This will be a launchpad for the new Angara rocket, set to replace Proton workhorse rockets.
Visiting late in the evening, the president viewed the floodlit site from a helicopter as well as on the ground, as workers used blowtorches on reinforced concrete.
The prospect of Putin's latest visit prompted a flurry of work, said independent space expert Vitaly Yegorov.
"You could say Putin's visit stimulated the start of building on the second phase of the space port. They finally started laying the concrete," he told AFP.
Putin publicly scolded officials when the first unmanned launch took place in 2016. The second unmanned launch in 2017 ended in the loss of contact with a string of satellites.
Since 2012, thousands of workers have been building roads and railway lines in the sparsely populated region as well as a new town for 25,000 people and create a new centre for the space industry.
The national space programme has suffered a series of setbacks in recent years including a manned launch failure -- the first of its kind in the history of Russian space travel, although the astronauts ejected safely.