NATO Secretary General Jens Stoltenberg to discuss how NATO members have bolstered their spending, the latest on the war in Ukraine and how the alliance can counter aggression from countries like Russia and China. Explosions reverberated across the pre-dawn sky as Ukrainian air defenses fended off a Russian attack on this small city in western Ukraine, home to an important air base and a frequent target of Moscow's strikes. Hours after the assault, the tidy streets of Starokostiantyniv had returned to a semblance of normality. But the June 27 attack was a stark reminder of the challenges Kyiv faces as it rebuilds its depleted air force and deploys the first U.S.-designed F-16s - fighter aircraft that Russia will be determined to ground or destroy. The first planes are expected to arrive this month, and Ukraine hopes they will boost forces struggling to repel a Russian onslaught along the front line, which includes devastating glide bombs that F-16s could potentially disrupt.