Air Force spokesman: S-300 missiles used to attack Kharkiv

"We want to understand what is happening, why it's happening, and where all this is heading," Zelensky told a bipartisan group of U.S. senators and representatives.

"Russia, frankly, has been fine on Ukraine. They haven't been doing much," Trump said, hours after a Russian drone strike in a public park killed six people, including two children.

The conversation with Zelensky comes three days after the pope spoke with Russian President Vladimir Putin to call for a ceasefire to evacuate civilians from the front-line town.

Three military personnel and three personnel were injured and are receiving treatment. The gunman has been detained and investigation is underway.

The EU has demanded a reform of Ukraine's notoriously corrupt and politicized prosecution service and called for making the procedure for picking the prosecutor general less political and more merit-based. Meanwhile, anti-corruption activists and pro-reform lawmakers have accused the Ukrainian authorities of sabotaging rule of law reforms and resisting the demand for depoliticizing the Prosecutor General's Office.

At least 550,000 households lost power overnight, Zelensky said, following a coordination meeting on the situation in Ukraine's regions.

The drone struck the town's central park while many people, including families with children, were there, Interior Minister Ivan Vyhivskyi said. An infant in a stroller and two women were among those killed, he added.

The captain was charged with violating the procedure for entering and exiting Ukraine's temporarily occupied territory with intent to harm the interests of the state, and violating the laws and customs of war.

Under a mechanism developed by Ukraine’s Infrastructure Ministry, Kyiv will compensate shipowners, operators, and charterers whose vessels fly under the Ukrainian or a foreign flag for up to 80% of the assessed damage if insurers don’t cover the risks.

Several explosions rocked the capital just before 11 p.m., with further attacks around 3 a.m. and 7 a.m., Kyiv Independent journalists on the ground reported. Ukraine's State Emergency Service (DSNS) said damage was reported in at least three districts.

The two sides are discussing a local ceasefire to allow residents to be evacuated directly to Ukrainian-controlled territory, Lubinets said on Oct. 18.