Britain's Defense Ministry speculates that Russian forces have likely increased their assaults over the past five days in the Donetsk sector of the Donbas region in eastern Ukraine.

The ministry said in a social media post on Saturday, that "There is a realistic possibility that Russia has increased its efforts in the Donbas in an attempt to draw in or fix additional Ukrainian units amid speculation that Ukraine is planning a major counter-offensive."

Russian forces are said to be trying to counter moves by Ukrainian forces attempting to fight back in southern Ukraine.

Rafael Grossi, the Director General of the International Atomic Energy Agency, said he intends to visit the Zaporizhzhia nuclear power plant in southeastern Ukraine with a team of experts to determine the plant's safety.

Ukraine's state nuclear power company Energoatom said Russian forces have pressured workers at the plant to prevent them from speaking out about criminal acts allegedly committed by the Russian troops there, who it said could be using the plant as a military facility.

Russia is reportedly preparing to hold referendums in parts of Ukraine under its control as early as September 11, with the aim of annexation.

But some analysts say it is becoming increasingly difficult for Russia to carry out referendums as planned amid growing Ukrainian resistance.