UK pledges missiles to Ukraine; new US ambassador in Kyiv

Britain pledged Thursday to send sophisticated medium-range rocket systems to Ukraine, joining the United States and Germany in equipping the embattled nation with advanced weapons for shooting down aircraft and knocking out artillery.

Western arms have been critical to Ukraine’s success in stymieing Russia’s much larger and better-equipped military during a war now in its 99th day. But as Russian forces closed in on a key city in recent days, the Ukrainian government said its fighters needed better rocket launchers to prevail.

A Kremlin spokesman again warned of “absolutely undesirable and...