Russia-Ukraine updates: Putin says 'certain positive movements' in negotiations

The Russian Defense Ministry claimed on Monday that it took control over Ukraine's Zaporozhye Nuclear Power Plant, the largest in Europe. 

Russian military claimed it took control of the cities of Energodar and Berdyansk and the territory around the power plant, Major General Igor Konashenkov, the representative of the Russian Defense Ministry said in an official statement. 

"The NPP staff continues to work on maintenance of facilities and monitoring of the radioactive situation in the normal mode. The radioactive background is normal," Konashenkov said.

The International Atomic Energy Agency confirmed Russia informed the body that its forces took control over the plant, Director General Rafael Mariano Grossi said on Wednesday. 

In an official letter to the Director General dated Tuesday, the Permanent Mission of the Russian Federation to the International Organizations in Vienna also said personnel at the plant continued their “work on providing nuclear safety and monitoring radiation in normal mode of operation. The radiation levels remain normal.”

Earlier on Tuesday, Ukraine informed the IAEA that all its nuclear power plants remained under the control of the national operator, the IAEA said on Wednesday. 

In an update on Wednesday, the State Nuclear Regulatory Inspectorate of Ukraine informed the IAEA that it maintained communications with the country's nuclear facilities and that they continued to operate normally. 

The Zaporozhye plant contains six out of the country's 15 nuclear energy reactors, according to the IAEA. 

Ukraine has not released a statement confirming or denying Russia's claims.

—ABC News' Tanya Stukalova

Ukraine will send a delegation on Wednesday to meet with Russia for a second round of talks aimed at stopping the fighting, a spokesman for Ukraine President Volodymyr Zelenskyy has told ABC News.

Russia earlier announced it was sending a delegation to sit and wait for possible talks but that Ukraine had not confirmed it would talk part in the negotiations. 

Ukraine and Russia held talks on the Belarus-Ukraine border two days ago but without a breakthrough, according to officials.

Ukraine's foreign minister Wednesday morning said it was ready to negotiate but not to accept Russian ultimatums. 

-ABC News' Patrick Reevell

Some 836,000 people have fled Ukraine since Russia launched an invasion there on Feb. 24, according to the latest figures from the United Nations High Commissioner for Refugees (UNHCR).

About 453,000 of them have gone to neighboring Poland, UNHCR said.

More than 4 million refugees from Ukraine may need protection and assistance in neighboring countries in the coming months. Meanwhile, an estimated 12 million people in Ukraine are in need of emergency assistance and protection, according to UNHCR.

-ABC News' Zoe Magee

Children in Ukraine "are in grave danger, especially from the threat of explosive weapons," international humanitarian group Save the Children warned Wednesday.

"Children injured in conflict zones are at even greater risk than adults due to their specific vulnerabilities and treatment needs for blast wounds," Save the Children said in a statement. "Younger children injured in blasts are particularly at risk of death compared to adults and need to be treated differently."

At least 14 children have been killed in Ukraine since Russia launched its invasion on Feb. 24, according to the United Nations.

Save the Children, which has been delivering essential humanitarian aid to children and their families in Ukraine since 2014, called for an immediate end to violence amid fears that many more lives are at risk as Russia's military operation intensifies in major cities and satellite images purportedly show a miles-long convoy of Russian forces closing in on the Ukrainian capital, Kyiv.