Former US president Donald Trump has said he was "very offended" by Russian president Vladimir Putin's endorsement of his Democratic rival, Vice President Kamala Harris.
Mr Trump's comments come after Mr Putin, in a teasing comment earlier this week, said Russia wants Ms Harris to win the US presidential election and cited her "infectious" laugh as a reason to prefer her over Donald Trump.
"He endorsed Kamala. I was very offended by that. I wonder why he endorsed Kamala. No, he's a chess player," Mr Trump told supporters at a rally in Mosinee, Wisconsin, before questioning whether Mr Putin made the remark "with a smile".
Mr Putin made the remark a day after the US Justice Department charged two Russian media executives over an alleged illegal scheme to influence the November election with pro-Russian propaganda.
It comes after former Republican Vice President Dick Cheney has said he will vote for Ms Harris over Mr Trump, following a similar statement made by his daughter Liz Cheney.
Ms Harris said endorsements of her by Mr Cheney and his daughter, a former US Representative, were "courageous" for putting country ahead of political party.
Meanwhile, former president George W Bush, a Republican, does not plan to make an endorsement or voice how he or his wife Laura will vote in the presidential election in November, a spokesman said.
"He retired from presidential politics many years ago," said the spokesman, who did not wish to be named.
Read more: Tuesday's debate could prove vital in tight US Presidential race
Mike Pence, who served as Mr Trump's vice president for four years, has said he will not endorse his former boss but has not backed Ms Harris.
Ms Harris and her running mate Tim Walz will tour several battleground states after her highly anticipated debate on Tuesday with Mr Trump, her campaign has said.
With less than 60 days until the 5 November election, Ms Harris will kick off the tour in North Carolina on Thursday and travel to Pennsylvania on Friday. Mr Walz will travel to Michigan and Wisconsin.
Polling averages show a tight race in the handful of states that could swing to Republicans or Democrats and will likely determine the election. The battleground states also include Georgia, Wisconsin and Arizona.
A key test for the candidates will come at their televised debate, the first since President Joe Biden dropped out of the race and endorsed Ms Harris as his successor on 21 July.
Ms Harris' candidacy has re-energised Democrats and donors, and she has had a surge in opinion polls.
Her campaign raised $361m in August, leaving her with a clear cash advantage over Mr Trump.
