The war in Ukraine is entering a “decisive phase”, with Vladimir Putin’s launch of a new ballistic missile showing that the threat of global conflict is “serious and real”, Poland’s prime minister has said.

Recent events show that there is a real risk of a global conflict breaking out, Polish Prime Minister Donald Tusk said on Friday, after Russia fired a hypersonic intermediate-range ballistic missile at a Ukrainian city.

Russia's Foreign Ministry has condemned the opening of a US missile defence base in Poland, labelling it a provocation and threatening a possible strike against the facility. In response, Warsaw dismissed Moscow's claims as inadequate.

Russian President Vladimir Putin said Thursday that the conflict in Ukraine had characteristics of a "global" war and did not rule out strikes on Western countries.

In an address, Vladimir Putin announced retaliation for Ukraine's use of weapons received from Western partners. Conversely, Gen. Valerii Zaluzhnyi, the former commander-in-chief of the Armed Forces of Ukraine,