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.

Russia has captured more territory in eastern Ukraine, with Nato set to hold emergency talks next week amid warnings that Russia will increase the production of a new, hypersonic ballistic missile. Russia’s Defence Ministry said its forces have captured the settlement of Novodmytrivka in Ukraine’s Donetsk region,

In a stark warning to the West, President Putin said the attack with the intermediate-range Oreshnik missile was in retaliation for Kyiv’s use of U.S. and British longer-range missiles.