China's ambassador to the United Nations has urged those concerned to act with caution and work together to ensure the safety of nuclear facilities inside Ukraine.

"China is paying close attention to the latest developments in Ukraine, and expresses our concerns over the relevant reports about the Zaporizhzhia nuclear power plant," Zhang Jun, China's permanent representative to the UN, told a Security Council briefing on the safety of nuclear facilities in Ukraine.

According to information the International Atomic Energy Agency, or IAEA, received from the Ukrainian nuclear authority, the main equipment of the nuclear power plant remains intact, and the level of radiation unchanged, Zhang said.

"We also noticed the information and clarification provided by Russia on the relevant matters. China attaches great importance to nuclear safety and security and hopes that the parties concerned will act with great caution, and with specialized technical assistance from the IAEA Secretariat, work together to ensure the safety of relevant nuclear facilities inside Ukraine.

"The most important thing right now is to ease tension, avoid more civilian casualties, intensify diplomatic efforts, and get back as soon as possible to the track of political settlement."

Russia and Ukraine had held two rounds of talks, he said.

"We encourage Russia and Ukraine to remain committed to the overall direction of political settlement and reach a negotiated solution that accommodates the legitimate concerns of the two parties and contributes to Europe's lasting peace and security."

China welcomes all diplomatic efforts conducive to a political settlement, he said. "We have played and will continue to play a constructive role to this end."

Ukrainian authorities on Friday said the Russian military had captured the Zaporizhzhia nuclear power plant, the largest in Europe, in southern Ukraine. The plant was seized following shelling that caused a fire at the plant, the State Nuclear Regulatory Inspectorate of Ukraine said.

Russia's Defense Ministry spokesman Igor Konashenkov confirmed on Friday that Russia's armed forces had taken control of the power plant.

The plant's six reactors were not affected by the fire, which had been extinguished, the IAEA Director-General Rafael Grossi said.

The plant normally provides more than half of Ukraine's nuclear power and contributes nearly 25 percent to its electric power.