(REUTERS) - Four-time Formula One champion Sebastian Vettel said he will not take part in the Russian Grand Prix even if it goes ahead as planned after Russia invaded neighbouring Ukraine on Thursday (Feb 24).

Russia has held grand prix races since 2014, with this year's event scheduled for Sept 25.

Formula One officials have said they are "closely watching" developments, but they have not commented on whether the Russian GP would go ahead as scheduled in September.

"My own opinion is I should not go," the 34-year-old German, who races for Aston Martin, told reporters during pre-season testing in Barcelona.

"I think it's wrong to race in the country. I'm sorry for the innocent people that are losing their lives, that are getting killed for stupid reasons and a very, very strange and mad leadership."

Reigning world champion Max Verstappen agreed.

"When a country is at war, it's not correct to race there, that's for sure," said the Dutchman who drives for Red Bull.

Western sanctions against Russia are likely to include measures against more Russian banks including VTB, the title sponsor of the Russian GP.

The race, set to move to a track outside St Petersburg starting next year from its current Sochi Olympic Park venue, has been attended by Russian President Vladimir Putin in the past. He has also handed out trophies on the podium.

"Formula One is closely watching the very fluid developments," the sport's commercial rights holder, which was acquired by the United States-based Liberty Media in 2017, said in a statement without mentioning the September race.

Formula One also includes Russian driver Nikita Mazepin, a 22-year-old who drives for the US-owned Haas team, whose title sponsor is Russian potash producer Uralkali, owned by his father and billionaire Dmitry Mazepin.

Earlier, Sky Sports had reported that Nikita is confident the Russian GP will go ahead and that he is a "supporter of sport without politics".

Haas team boss Guenther Steiner had been scheduled to appear at a press conference on Thursday but was withdrawn from the line-up.