Anti-graft watchdog Transparency International (TI) warned on Tuesday of worsening corruption in democracies worldwide and said the United States had slid to the lowest-ever score on its 2025 Corruption Perceptions Index.

Berlin-based TI also said the average global score had hit its worst level, 42, in more than a decade. The global average score was 42, its lowest level in more than 10 years, with the findings of between zero (highly corrupt) and 100 (very clean) based on data reflecting the assessments of experts and business executives.

US President Donald Trump, since returning to the White House early last year, has upended domestic and foreign politics while ramping up pressure on institutions ranging from universities to the Federal Reserve.

Fed chairman Jerome Powell is currently under investigation by Trump's Department of Justice after resisting pressure from the president to reduce interest rates.

TI raised concerns over "actions targeting independent voices and undermining judicial independence" in the United States.

"The temporary freeze and weakening of enforcement of the Foreign Corrupt Practices Act signal tolerance for corrupt business practices," said the watchdog, with its data sources have previously included the World Economic Forum and the Economist Intelligence Unit.

The Trump administration's gutting of overseas aid has also "weakened global anti-corruption efforts", it said.

The US has dropped to a score of 64, with the report noting that its "political climate has been deteriorating for more than a decade".

"The vast majority of countries are failing to keep corruption under control," the report said, with 122 countries out of 180 posting scores under 50 and Denmark remaining the highest-ranked nation for the eighth year running with a score of 89.

The US case illustrates a trend in democracies experiencing a "decline in performance" in battling corruption, according to the report, a phenomenon it also said was apparent in the UK and France.

While such countries are still near the top of the index, "corruption risks have increased" due to weakening independent checks, gaps in legislation and inadequate enforcement.

"Several have also experienced strains to their democracies, including political polarisation and the growing influence of private money on decision-making," the report noted. (AFP)