NATO¡¯s top official on Tuesday called on allies to step up arms supplies to the Ukrainians, especially sophisticated air defense systems, a day after Russia rained rocket fire on 19 cities across Ukraine in a marked escalation of its assault on civilians.

As missiles and rockets continued to strike Ukraine, although in smaller numbers than Monday, NATO Secretary-General Jens Stoltenberg said that Moscow¡¯s aerial attacks on civilian targets were ¡°a sign of weakness¡± and that Ukraine would be better able to deter them if its existing weaponry was expanded.

¡°These air defense systems are making a difference because many of the incoming missiles were actually shot down by Ukrainian air defense systems provided by NATO allies,¡± he said.