Russian forces launched missile strikes on at least five Ukrainian cities late Wednesday and early Thursday, just hours before Ukrainian President Volodymyr Zelenskyy's planned meeting with U.S. President Joe Biden in Washington, D.C.

Ukrainian Foreign Minister Dmytro Kuleba, who is traveling with Zelenskyy in the United States, described the strikes as "a massive missile attack" on civilian infrastructure, while Ukrainian state-owned grid operator Ukrenergo said it's the first major attack on the country's energy infrastructure in six months.

Russian forces fired a total of 43 missiles across Ukraine from east to west, and 36 of them were shot down by Ukrainian air defense, according to Gen. Valeriy Zaluzhny, commander-in-chief of the Ukrainian Armed Forces. The Ukrainian capital of Kyiv was among the major cities hit, along with areas of Kharkiv, Kherson, Cherkasy, Rivne and Lviv.

Ukrainian authorities were still assessing the damage and casualties on Thursday morning, but dozens of injuries have been reported so far. At least seven people were injured by falling debris in Kyiv.

Meanwhile, rescue efforts were ongoing in the central city of Cherkasy to evacuate as many as 20 people believed to be trapped beneath the rubble of a hotel that was destroyed in the strikes overnight. Thirteen others were already rescued and at least nine were injured, according to Ukrainian officials

The overnight strikes also targeted energy infrastructure in the Rivne region and an industrial zone in the Lviv area.

-ABC News' Victoria Beaulé, Guy Davies, Yulia Drozd and Tatyana Rymarenko.

Russian forces initiated six strikes on Kharkiv overnight, damaging civilian infrastructure, Ukrainian officials said early Thursday.

The mayor of Kyiv also said explosions occurred in the Ukrainian capital overnight. Debris from the downed rockets fell in the Darnytskyi and Holosiivskyi districts of the city.

Five people were hurt in the Darnytskyi district of Kyiv, where the strike also destroyed non-residential buildings. Three of them, including a 9-year-old girl, were hospitalized. Two were treated by medics on scene.

In the Shevchenkivskyi district of Kyiv, rocket debris damaged a gas pipe, an official said.

-ABC News' Will Gretsky

Seventeen people were killed, and 32 others injured, when a Russian missile hit a market in the center of Kostyantynivka in the Donetsk region, according to Ukrainian officials.

"At this moment, the artillery of Russian terrorists has killed 16 people in the city of Kostiantynivka, Donetsk region," President Volodymyr Zelenskyy said on Telegram. "A regular market. Shops. A pharmacy. People who did nothing wrong. Many wounded. Unfortunately, the number of casualties and the injured may rise."

Ukrainian President Volodymyr Zelenskyy visited troops at the front line near Bakhmut as Ukrainian forces continue to make ground in their counteroffensive, the president's office said Tuesday.

Zelenskyy, who was accompanied by commander of ground forces Col. Gen. Oleksandr Syrskyi, thanked soldiers for their service and presented them with awards, according to a video released by the office.

"I awarded the best warriors. And I thank everyone who fights for the sake of the state," Zelenskyy said.

Ukrainian defense forces continue to advance in the direction of Melitopol, according to the spokesman for Pavlo Kovalchuk, the general staff of the Armed Forces of Ukraine.

"They were successful in the direction of Robotyne - Novoprokopivka. They are entrenching at the achieved milestones," the spokesman said.

-ABC News' Will Gretsky

Ukrainian President Volodymyr Zelenskyy spoke out against American critics who are pushing for cuts to military support to his country stating there are "dangerous voices" in Congress and in the U.S.

Zelenskyy told reporters Wednesday that his team was in constant contact with National Security Advisor Jake Sullivan and other U.S. national security officials, stating he was "glad" Ukraine had the backing of the White House, enjoyed bipartisan support in Congress and received “a lot” of support from the American public.

However, Zelenskyy said the coming year will be "very difficult," referring to the U.S. presidential election, which "will definitely have an impact on support for Ukraine."

"I think we’re going to have a hard time," Zelenskyy said.

He said the election results could be positive or negative for Ukraine.

“For our part, we will do everything to ensure that the support of the United States does not decrease…we will give all our time, our energy to constantly work with the USA," Zelenskyy said. “I expect that our partners in the United States will continue to be our partners and friends.”

Zelenskyy said Ukraine was working on lobbying Biden for longer range missiles.

-ABC News' Tom Buridge and Natalya Kushnir