The attack in the Caspian Sea was an unusually direct encounter between two countries that have been on opposite sides for years.

Iran is threatening retaliation against Ukraine after Kyiv acknowledged striking an Iranian vessel in the Caspian Sea over the weekend, escalating concerns that the attack could expand into a more direct confrontation across the globe.

In an interview with NPR, one of Ukraine's top negotiators Sergiy Kyslytsya explains why Kyiv believes it now has the leverage to force Russia into serious negotiations.

All the ballistic missiles launched by Russia struck their targets, underscoring Kyiv's need for more U.S. Patriot interceptor missiles, Ukraine officials say.

Serious destruction' — massive Russian missile, drone attack on Kyiv kills at least 30, injures over 90; * Ukraine urgently appeals to nearly 40 allies for Patriot

The Patriot is currently the only ground-based system proven to intercept Russian ballistic missiles in Ukraine.

Russia launched a massive attack on Ukraine's capital, killing at least 21 people and prompting President Zelenskyy to call for sped-up weapons support from his partners.

Ukraine’s air force said Tuesday it intercepted five ballistic missiles launched by Russia in a raft of overnight attacks, although other missiles and drones got through and hit warehouses and a school in the capital of Kyiv.