Ukrainian Defense Minister Oleksii Reznikov said Friday the military is "ready" to launch a counteroffensive against Russian forces.

"It's up to the general staff and the command," Reznikov said during a press briefing in Kyiv. "We will do it as soon as there is God's will, the weather and the commanders' decision."

Ukraine has received Patriot missile defense systems from the United States as well as Germany and the Netherlands. The Ukrainian military has been trained on how to use the systems and "mastered" them within weeks, according to Reznikov.

"The exact number of batteries, I'm sorry, I won't say," he added. "Let the enemy guess."

Meanwhile, Ukrainian Foreign Minister Dmytro Kuleba urged the world not to consider or call the anticipated counteroffensive "a decisive battle." Speaking at a press conference in Odesa on Friday, Kuleba said the decisive battle is the one that will lead to the liberation of all occupied Ukrainian territories.

-ABC News’ Will Gretsky

One person was killed and 23 people, including a child, were wounded in a Russian missile strike in Mykolaiv early Thursday, Ukrainian President Volodymyr Zelenskyy said.

The missile struck a block that had apartments, houses and a historic building, according to Zelenskyy.

"The terrorists will not get away with this yet another crime against humanity," the president said in a statement.

-ABC News' Will Gretsky

Ukrainian President Volodymyr Zelenskyy spoke with Chinese President Xi Jinping in what was the two leaders' first official contact since January 2022, before Russia's invasion of Ukraine.

Xi announced that he will send a special envoy to visit Ukraine and "other countries" to work on a political solution.

"I believe that this call, as well as the appointment of Ukraine's ambassador to China, will give a powerful impetus to the development of our bilateral relations," Zelenskyy said in a statement on Twitter.

The Chinese government's official position still refuses to call the war an "invasion."

The call between the two leaders is said to have lasted an hour, according to Zelenskyy's office.

"Before the full-scale Russian invasion, China was Ukraine's number one trading partner. I believe that our conversation today will give a powerful impetus to the return, preservation and development of this dynamic at all levels," Zelenskyy said in a statement.

-ABC News' Karson Yiu, Cindy Smith and Will Gretsky

At least two people were killed and 10 injured after a Russian missile hit a Ukrainian museum Tuesday, officials said.

The local history museum is located in the city center of Kupiansk, in the Kharkiv region.

"The terrorist country is doing everything to destroy us completely. Our history, our culture, our people," Ukrainian President Volodymyr Zelenskyy said on social media while sharing a video that showed the damaged building. "Killing Ukrainians with absolutely barbaric methods."

U.S. Secretary of State Antony Blinken urged the Kremlin to release imprisoned Wall Street Journal reporter Evan Gershkovich in a phone call Sunday with his Russian counterpart, according to a State Department spokesperson.

Blinken spoke with Russian Foreign Minister Sergey Lavrov, conveying the United States' "grave concern" over the "unacceptable detention" of a U.S. citizen, according to Vedant Patel, a deputy spokesperson for the State Department.

"The secretary called for his immediate release. Secretary Blinken further urged the Kremlin to immediately release wrongfully detained U.S. citizen Paul Whelan," said Patel, referring to the American held in Russia on espionage charges since 2018.

According to a read out of the phone call released by the Kremlin, Lavrov emphasized that Gershkovich "was taken red-handed while trying to obtain classified information, collecting data constituting a state secret under the guise of journalistic status."

"In the light of the established facts of illegal activity of a U.S. citizen, of whose detention the U.S. Embassy in Moscow was notified in accordance with the established procedure, his further fate will be determined by the court," the Kremlin said in a statement.

The Kremlin said that during the conversation, Lavrov emphasized officials in Washington and the Western media are "escalating the hype with the clear intention of giving this case a political coloring."

Blinken and Lavrov also spoke of the "importance of creating an environment that permits diplomatic missions to carry out their work," according to Patel.