The UK and US have accused Russia of launching a weapon-like projectile from a satellite in space.
In a statement, the head of the UK's space directorate said: "We are concerned by the manner in which Russia tested one of its satellites by launching a projectile with the characteristics of a weapon."
The statement said actions like this "threaten the peaceful use of space". The US has previously raised concerns about this Russian satellite.
Air Vice Marshal Harvey Smyth, head of the UK's space directorate, said in a statement: "Actions like this threaten the peaceful use of space and risk causing debris that could pose a threat to satellites and the space systems on which the world depends.
"We call on Russia to avoid any further such testing. We also urge Russia to continue to work constructively with the UK and other partners to encourage responsible behaviour in space."
Meanwhile the Russian State Space Corporation has released pictures of its Soyuz rocket lifting off from the launch pad at the Baikonur cosmodrome in Kazakhstan today.
The vessel, called Progress MS-15, will deliver more than 2.5 tonnes of cargo to the International Space Station.
Also today, US President Donald Trump told his Russian counterpart Vladimir Putin that he hopes to avoid an "expensive" US arms race with Russia and China, the White House said.
Washington and Moscow are preparing negotiations on a successor to the New START treaty capping their countries' nuclear arsenals.
However, China has so far rejected pressure from the Trump administration to join the talks, saying that its arsenal is far smaller than that of the two former Cold War foes.
Mr Trump "reiterated his hope of avoiding an expensive three-way arms race between China, Russia, and the United States and looked forward to progress on upcoming arms control negotiations in Vienna," a White House spokesman said.
According to the Kremlin, the two leaders confirmed the "urgency" of holding bilateral talks on "strategic stability and arms control".
They also discussed "the situation around the Iranian nuclear programme" and underlined the "need for collective action," the Kremlin statement continued.