Russian forces seize two cities in Ukraine as ceasefire talks begin

The goal was an immediate ceasefire and the withdrawal of Russian forces, the Ukrainian president's office said earlier.

Russian forces seized two small cities in southeastern Ukraine and the area around a nuclear power plant, the Interfax news agency said on Monday, but ran into stiff resistance elsewhere as Moscow's diplomatic and economic isolation deepened.

After four days of fighting and a Russian advance that has gone more slowly than some expected, talks between Ukraine and Russia started on Monday at the border with Russian ally Belarus, a senior Ukrainian official told Reuters via text message.

The goal was an immediate ceasefire and the withdrawal of Russian forces, the Ukrainian president's office said earlier.

It was not clear whether any progress could be achieved after President Vladimir Putin on Thursday launched the biggest assault on a European state since World War Two and put Russia's nuclear deterrent on high alert on Sunday.

The Western-led response was swift, with sanctions that effectively cut off Moscow's major financial institutions from Western markets sending Russia's rouble currency down 30% against the dollar on Monday. Countries also stepped up weapons supplies to Ukraine.

Blasts were heard before dawn on Monday in the capital of Kyiv and in the major eastern city of Kharkiv, Ukrainian authorities said. But Russian ground forces' attempts to capture major urban centres had been repelled, they added.

Russia's defence ministry, however, said its forces had taken over the towns of Berdyansk and Enerhodar in Ukraine's southeastern Zaporizhzhya region as well as the area around the Zaporizhzhya nuclear power plant, Interfax reported. The plant's operations continued normally, it said.