A cable to more than 20 US embassies from Argentina and Mexico to Italy and Albania was sent by the US State Department in mid-June. It requested information on left-wing extremist groups, The Washington Post reports.
Several embassies have responded, but none have stated that they agree with the administration's assessment of the threat level.
But the US sees it differently. Secretary Marco Rubio has invited senior ministers from more than 60 countries to a meeting next week to discuss what the Trump administration considers a major threat: "the resurgence of far-left transnational terrorism."
The meeting has raised concerns among current and former U.S. officials, European allies and independent analysts who do not see the threat in the same light. Some U.S. officials told the newspaper they fear it is part of an effort by the Trump administration to use its powerful counterterrorism tools against American activists it considers left-wing extremists.
State Department spokesman Tommy Pigott said the meeting was organized because far-left terrorism is "an old threat that is making a comeback with strong transnational ties and new forms of cooperation."
"Because this threat has not been adequately addressed in the past, any commitment, announcement or security assistance program creates a multiplier effect that supports measures against this phenomenon, both domestically and internationally," Pigott stated.
In several meetings of national security officials, intelligence analysts have refused to report on Antifa, as they do not consider it a serious threat to counterterrorism, according to a person familiar with the matter.
Antifa, short for "anti-fascist", is a decentralized movement without a clear command or leadership structure, encompassing a wide range of ideologies, mostly left-wing, from anarchism to communism. Unlike the left-wing extremist groups of the 1960s and 1970s, Antifa does not publish manifestos and does not take responsibility for its actions.
Some foreign governments have also expressed surprise at Rubio's invitation. Speaking on condition of anonymity, European officials described the meeting's objective as unclear and criticized the short notice. The invitation was sent last week and responses were requested by Friday.
Some of them said that their countries' foreign or interior ministers are not expected to attend due to a busy diplomatic agenda over the summer, which includes the annual security conference in Aspen, Colorado.
Some diplomats said they did not understand why they had been invited.
"We don't have Antifa," said a European diplomat.
"We see no reason why we would be interested in participating in such a meeting," said another.
“Our law enforcement agencies are not focused on far-left terrorism because it is not considered a priority threat to our country,” a third diplomat said.
The guest list, reviewed by The Washington Post, includes most European countries, most major Latin American states and several Asian countries, including India, Indonesia and Singapore. The State Department did not respond to questions about the criteria used to compile the list.