NEW YORK -- Three Russian cosmonauts arrived at the International Space Station on Friday wearing yellow flight suits with blue accents, colours that appeared to match the Ukrainian flag. The men were the first new arrivals on the space station since the start of the Russian war in Ukraine last month.

Russian space corporation Roscosmos cosmonauts Oleg Artemyev, Denis Matveyev and Sergey Korsakov blasted off successfully from the Russia-leased Baikonur launch facility in Kazakhstan in their Soyuz MS-21 spacecraft at 8:55 p.m. Friday (11:55 a.m. EDT). They smoothly docked at the station just over three hours later, joining two Russians, four Americans and a German on the orbiting outpost.

Video of Artemyev taken as the spacecraft prepared to dock with the space station showed him wearing a blue flight suit. It was unclear what, if any, message the yellow uniforms they changed into were intended to send.

When the cosmonauts were able to talk to family back on Earth, Artemyev was asked about the suits. He said every crew chooses their own.

鈥淚t became our turn to pick a color. But in fact, we had accumulated a lot of yellow material so we needed to use it. So that's why we had to wear yellow,鈥 he said.

Since the war started, many people have used the Ukrainian flag and its colors to show solidarity with the country.

The war has resulted in canceled spacecraft launches and broken contracts. Roscosmos chief Dmitry Rogozin has warned that the U.S. would have to use 鈥渂roomsticks鈥 to fly into space after Russia said it would stop supplying rocket engines to U.S. companies. Many worry, however, that Rogozin is putting decades of a peaceful off-planet partnership at risk, most notably at the space station.

NASA Administrator Bill Nelson played down Rogozin's comments, telling The Associated Press: 鈥淭hat's just Dmitry Rogozin. He spouts off every now and then. But at the end of the day, he's worked with us.鈥

鈥淭he other people that work in the Russian civilian space program, they're professional,鈥 Nelson told the AP on Friday. 鈥淭hey don't miss a beat with us, American astronauts and American mission control. Despite all of that, up in space, we can have a cooperation with our Russian friends, our colleagues.鈥

NASA astronaut Mark Vande Hei - who on Tuesday broke the U.S. single spaceflight record of 340 days - is due to leave the space station with two Russians aboard a Soyuz capsule for a touchdown in Kazakhstan on March 30.

In April, another three NASA and one Italian astronaut are set to blast off for the space station.