Carlos Sainz will make an early switch to Renault at the United States Grand Prix after the team agreed to part ways with Jolyon Palmer.

The team confirmed last month that Sainz would replace the struggling Palmer for 2018, but there was speculation that the Spaniard would jump ship for the Malaysian Grand Prix.

That did not materialise, with Palmer maintaining that he would see out the season with the French manufacturer.

However, after qualifying for the Japanese Grand Prix, Palmer announced that Sunday's race would be his last this season.

"The Japanese Grand Prix will be my last race for Renault," his statement read.

"It's been an extremely challenging season and I've been through a lot in the last three years, but it's been a tremendous journey overall with the team. 

"I can look back at the performance in the second half of last season, my first point in Malaysia and of course reaching a career high of sixth place in Singapore this year. 

"I wish the team all the best for the future. My immediate focus is now on achieving the best possible result in the Japanese GP, and then I can assess my options for the future. "

Sainz's premature move means Daniil Kvyat, who had been dropped so the team could evaluate Pierre Gasly, will return in Austin.

Gasly, meanwhile, will miss the Super Formula finale and thereby forfeit a potential title.