The US presidential election will pose the greatest political risk to the world in 2024 no matter who wins, with institutions of the most powerful democracy certain to take a beating, the Eurasia Group said Monday.

In an annual report, the political risk consultancy said that the November 5 election "will test American democracy to a degree the nation hasn't experienced in 150 years," a reference to the country's civil war.

"The United States is already the world's most divided and dysfunctional advanced industrial democracy. The 2024 election will exacerbate this problem no matter who wins," it said.

"With the outcome of the vote essentially a coin toss (at least for now), the only certainty is continued damage to America's social fabric, political institutions and international standing."

If Donald Trump — currently the Republican front-runner — again loses to President Joe Biden, the real estate mogul will likely once more allege massive fraud and "incite widespread intimidation campaigns" against election officials and workers, the report said.

The United States in a Biden second term could also face an "unprecedented political crisis" if Trump goes to jail on one of myriad cases in which he is charged, although large-scale violence remains unlikely, it said.

Biden has cast his campaign as a struggle to save democracy against Trump, whose supporters attacked the US Capitol on January 6, 2021, in hopes of stopping the formalization of Biden's victory.

If he loses, Biden would be expected to concede. But many Democrats will also view Trump as illegitimate and some will refuse to confirm his victory citing the constitutional prohibition against anyone who has "engaged in insurrection" taking office, the Eurasia Group said.

Meanwhile, a second-term Trump would be expected to "weaponize" the US government to go after rivals and crush dissent, it added.

The Eurasia Group ranked the violence in the Middle East as the second greatest global risk, with the Israel-Hamas war "likely to be only the first phase in an expanding conflict in 2024."

The third greatest risk was Ukraine, with the study predicting the country in 2024 will in effect become partitioned with Kyiv struggling to retake remaining areas seized by Russia.

It said Ukraine would face another major blow if the United States elects Trump, who opposes the billions of dollars in US aid to Kyiv.