President Vladimir Putin said Friday that Russia will continue to test and start mass-producing the hypersonic ballistic missile that it fired at Ukraine Thursday.

Tit-for-tat moves this week included the use of American-made ballistic missiles to strike inside Russia, and new nuclear threats from Moscow. Neither appear to have influenced the war on the ground.

The Kremlin fired a new intermediate-range ballistic missile at Ukraine on Thursday in response to Kyiv's use this week of American and British missiles capable of striking deeper into Russia, President Vladimir Putin said.