The U.S. supports efforts in Cambodia to combat terrorism, build democratic institutions, promote human rights, foster economic development, and eliminate corruption.

[1][2] According to a 2011 Gallup poll, 68% of Cambodians approved of the job performance of the United States under the Obama administration, with 7% disapproving, the most favorable opinion for any surveyed Asia–Pacific nation.

[5] However, the fact that this regime was toppled in the Cambodian–Vietnamese War by Vietnam, which the United States regarded as a hostile power, led to U.S. condemnation of the Vietnamese invasion.

After the factional fighting in 1997 and Hun Sen's legal machinations to depose First Prime Minister Norodom Ranariddh, the United States suspended bilateral assistance to the Cambodian Government.

Since 2017, relations between the two countries have grown increasingly strained under calls by the United States to halt what it says is significant democratic backsliding and closer military ties with the People's Republic of China.

[11] According to the U.S. State Department, the Cambodian government's crackdown on journalists, human rights activists, and political opposition has transformed the country from a developing democracy inclusive of independent media to a "de facto one-party—and increasingly authoritarian—state intolerant of dissent.

[13] In 2019, the Wall Street Journal published a report detailing a secret deal between Beijing and Phnom Penh to allow the stationing of PLA troops at Ream Naval Base.

[14] In 2020, Cambodia demolished a Cambodian Navy tactical headquarters funded and built by the United States and after broke ground on the new Beijing-funded Ream Naval Base.

[13][16] Following the 2023 general election, the U.S. took steps to impose visa restrictions on individuals it deemed had "undermined democracy" and also implemented a pause of certain foreign assistance programs.