Ukraine said the missile, without a nuclear warhead, targeted the central city of Dnipro. The Kremlin did not confirm it had deployed the weapon but said it was doing everything possible to avoid a nuclear conflict.

"While we're assessing the full facts, it's obvious that such (an) attack would mark yet another clear escalation from the side of Putin," EU foreign affairs spokesman Peter Stano told reporters.

Kyiv said several types of missiles were launched at the industrial city in the latest escalation since Ukraine fired Western-supplied long-range missiles on Russia, targeting critical infrastructure and leaving two people wounded.

If confirmed, the use of the intercontinental ballistic missile (ICBM), would represent a "quantitative and qualitative change" in the war, said Stano.

ICBMs can hit targets thousands of kilometres away and are designed to carry both conventional and nuclear warheads.

A source in the Ukrainian air force confirmed it was the first time such a weapon had been used since Russia invaded in February 2022, adding it was "obvious" that the missile did not carry a nuclear charge.

Russia updated its nuclear doctrine this week, allowing it to use nuclear weapons against non-nuclear states after the United States gave Kyiv permission to use its ATACMS against military targets inside Russia.

"They are playing a nuclear gamble," the EU's Stano said of Moscow. "Whether they really mean it, it's very hard to foresee. We don't see in their heads. We only know that this is irresponsible and this constitutes a global threat".