The State Department Wednesday called Ecuador's expulsion of a U.S. diplomat unjustified and said the United States will respond appropriately. The expulsion was the second of its kind this month.

The State Department is expressing regret over the latest expulsion and suggesting the United States will respond in kind. But it is also says the Obama administration wants good relations with the South American country and hopes to continue working with it to curb regional drug trafficking.

Officials here identified the U.S. diplomat ordered to leave Ecuador within 48 hours as Mark Sullivan, first secretary in the embassy's regional affairs office. A senior Ecuadoran official told reporters in Quito the American diplomat had been meddling in the country's police affairs.

In a talk with reporters, State Department Deputy Spokesman Gordon Duguid said the United States will comply with the expulsion order but denied Sullivan had been involved in any improper activities:

"We regret this decision by the government of Ecuador," said Gordon Duguid. "We also reject any suggestion of wrongdoing by the embassy staff. Despite the government of Ecuador's unjustified action, we remain committed to working collaboratively with Ecuador to confront narcotics trafficking."

Spokesman Duguid said the United States will respond to the expulsion in an appropriate way, diplomatic language suggesting an Ecuadoran diplomat in Washington may be asked to leave. However, he did not elaborate and said the matter is still under discussion.

Earlier this month, an employee of the U.S. Department of Homeland Security at the Quito embassy, Armando Astorga, was also ordered to leave the country under similar circumstances, with officials in Quito accusing him of using U.S. economic aid to try to influence the leadership of an Ecuadoran police unit.

A senior official here said in both cases, Ecuadoran authorities apparently objected to efforts by the U.S. diplomats to select among potential candidates in the Ecuadoran security forces for U.S.-sponsored anti-narcotics training. 

The official said Ecuadoran authorities did not like the vetting, but that the selection process is required by U.S. law to root out potentially corrupt officers or those with other problem issues.

The United State has had a difficult relationship with the left-leaning government of Ecuadoran President Rafael Correa, who was a persistent critic of the former Bush administration's Latin American policy.

President Correa has said his government will not renew an agreement that expires in November allowing U.S. Air Force planes to use Ecuador's Manta air base for anti-drug surveillance flights.