Russian Foreign Minister Sergey Lavrov has accused Western politicians of considering nuclear war.

“Everyone knows that World War Three can only be nuclear, but I would like to point out that it is in the heads of Western politicians, not in the heads of Russians,” Lavrov said at a press conference.

Lavrov added that plans for a "real war" against Moscow were being developed.

On Sunday, Russian President Vladimir Putin ordered Russia's nuclear forces be put on high alert.

Russia launched a military operation against Ukraine on February 24. At the beginning of the second week of Russian operation, the city of Kherson in southern Ukraine came under the control of Russia.

Despite the ongoing shelling and clashes, delegations from Russia and Ukraine will meet for a second round of negotiations on the Belarusian border this Thursday. The parties will talk about a possible ceasefire.

According to the Ukrainian emergency services, more than 2,000 civilians died because of the clashes. The United Nations reported that more than one million Ukrainians have taken refuge in neighbouring countries in a week.

Russia justifies its military operations by saying "it is freeing Ukrainians from oppression and the Nazi government", and halting NATO expansion towards its own borders.

In a recent video address, Ukrainian President Volodymyr Zelensky described Russia's attack as a "new virus".

“We have nothing to lose but our freedom. A new virus has been attacking us for a week,” Zelensky said.