A US astronaut and a Russian cosmonaut on Friday arrived in the Moscow region following a failed launch to the International Space Station that forced an emergency landing.

NASA's Nick Hague and Roscosmos' Alexei Ovchinin blasted off to the orbiting lab on Thursday but had to make an emergency landing in their capsule less than two minutes into the flight after their Soyuz rocket suffered an unspecified failure of its second stage.

Roscosmos director general Dmitry Rogozin, who traveled to Kazakhstan to bring the crew back, posted a picture of himself and the two men Friday, saying they are safely back in the Moscow region.

"The guys will definitely fly again," he tweeted.

Vyacheslav Rogozhnikov, chief of the Russian Federal Medical and Biological Agency, said on Russian state television that the two men are "in great health" and do not require medical treatment.

While the Russian program has been dogged by a string of problems with other kinds of launches in recent years, Thursday's incident was its first manned launch failure since September 1983, when a Soyuz exploded on the launch pad.

Roscosmos' executive director Sergei Krikalyov said in comments on state television that the rocket's failure happened after parts of the first and second stage came into collision.

"The details of the reason why — whether that was a cable or a nut — we need to look at it and analyze. We need more data," he said.

Roscosmos said on Thursday that it would suspended all manned flights to the space station pending the investigation, and Krikalyov said on Friday that the orbiting outpost could be switched into an unmanned mode if the investigation takes a while. But Russia would like to avoid mothballing the station, he said.