Former US President George W Bush has denounced bigotry in Trump-era American politics, warning that the rise of “nativism”, isolationism and conspiracy theories have clouded the nation’s true identity.

The comments, delivered at a New York City conference hosted by the George W Bush Institute, amounted to an indirect critique from a former Republican president who has remained largely silent during President Donald Trump’s unlikely rise to power.

The 43rd president did not name Mr Trump on Thursday, but he attacked some of the principles that define the 45th president’s political brand.

“We’ve seen nationalism distorted into nativism, forgotten the dynamism that immigration has always brought to America,” Mr Bush said.

“We see a fading confidence in the value of free markets and international trade, forgetting that conflict, instability and poverty follow in the wake of protectionism.

“We’ve seen the return of isolation sentiments, forgetting that American security is directly threatened by the chaos and despair of distant places.

“We’ve seen our discourse degraded by casual cruelty,” he continued.

“Bigotry seems emboldened. Our politics seems more vulnerable to conspiracy theories and outright fabrication.”

Asked about the speech, Mr Trump said he hadn’t seen it.

Mr Bush noted Russia’s meddling in the 2016 election and declared that “the Russian government has made a project of turning Americans against each other”.

Mr Bush is the brother of 2016 presidential hopeful Jeb Bush, the former Florida governor nicknamed, belittled and ultimately vanquished by Mr Trump during the race for the Republican nomination.

He joins a slowly growing list of prominent Republicans who have publicly defied Mr Trump, including John McCain and Bob Corker.

—AP