The United States (US) military said on Tuesday it will defend its satellite from a possible attack by Russia’s space weapon as Moscow launched a nuclear missile drill close to Ukraine.

“Russia launched a satellite into low Earth orbit that we assess is likely a counter-space weapon presumably capable of attacking other satellites in low Earth orbit,” Pentagon spokesperson Air Force Major General Pat Ryder told a press briefing late Tuesday.

The Russian “counter-space weapon” launched on 16 May was deployed “into the same orbit as a US government satellite,” he said.

Ryder added that Washington would continue to monitor the situation and was ready to protect its interests.

“We have a responsibility to be ready to protect and defend the domain, the space domain, and ensure continuous and uninterrupted support to the Joint and Combined Force,” he said.

Meanwhile, Russia on Tuesday announced the start of tactical nuclear weapons drills close to Ukraine, in what it said was a response to Western “threats.”

Throughout its two-year offensive on Ukraine, Moscow has repeatedly talked-up its arsenal of nuclear weapons and its readiness to deploy them if it senses an existential threat.

The West has accused President Vladimir Putin of irresponsible nuclear saber-rattling.

Russia’s defense ministry said Tuesday the drills were taking place in its Southern Military District, which borders and includes parts of Ukraine that Moscow claims to have annexed. It did not specify exactly where.

The drills are designed to test “the readiness of personnel and equipment of non-strategic nuclear weapons combat units to respond and to unconditionally ensure the territorial integrity and sovereignty of the Russian state,” the defense ministry said in a statement.

It added they were a “response to provocative statements and threats by certain Western officials.”

Putin ordered the drills earlier this month after a series of Western statements on the Ukraine conflict drew scorn in Moscow.

Russian officials pointed to comments by French President Emmanuel Macron about North Atlantic Treaty Organization countries needing to not rule out deploying troops to Ukraine and British Foreign Minister David Cameron saying Kyiv had the right to fire Western missiles at Russian territory.