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 says that the firing of a hypersonic missile and an address by Vladimir Putin are clear messages to the West - describing the move to let Ukraine use their weapons to strike Russia as "reckless".