The American arrested in Russia on suspicion of spying met with the United States ambassador on Wednesday, and the secretary of state said he would demand the man’s return if the detention was “not appropriate.”
Russia’s domestic security agency said on Monday that it had detained the American, Paul N. Whelan, three days earlier “during an act of espionage,” a crime that in Russia can carry a term of up to 20 years in prison. The agency, the Federal Security Service, or F.S.B., said it had opened a criminal case against Mr. Whelan but provided no other details.
On Tuesday, the State Department said it was still waiting for Russian authorities to provide consular access to Mr. Whelan, a Marine Corps veteran whose family said he was in Moscow to attend a wedding.
That access was granted on Wednesday, a State Department spokesperson said, when Ambassador Jon M. Huntsman Jr. visited Mr. Whelan at the Lefortovo Detention Facility in Moscow. Mr. Huntsman offered the American Embassy’s assistance, and later spoke with Mr. Whelan’s family by phone.
Secretary of State Mike Pompeo, in Brasília for the inauguration of President Jair Bolsonaro of Brazil, said on Wednesday that American diplomats had asked for explanations from their Russian counterparts.
“We’ve made clear to the Russians our expectation that we will learn more about the charges, come to understand what it is he’s been accused of,” Mr. Pompeo said at a news conference. “And if the detention is not appropriate, we will demand his immediate return.”
Mr. Whelan, 48, is the director of global security for BorgWarner, an auto-parts maker in Michigan. In a statement, his family said that he had been in Moscow for the wedding of another Marine veteran, whose party was staying at the Metropol hotel.
“We are deeply concerned for his safety and well-being,” the family statement said. “His innocence is undoubted and we trust that his rights will be respected.”
The timing of Mr. Whelan’s arrest raised concern in the West that his detention would be used by the Kremlin for political purposes, during a period of intensely strained relations with the United States over Russia’s actions abroad, including its efforts to influence American politics. Russia has denied any such interference.
Mr. Whelan was arrested 15 days after a Russian woman, Maria Butina, pleaded guilty in Washington to conspiring to act as a foreign agent, working with Russian officials to influence American political figures. She faces six months in prison, likely followed by deportation.
The Russian government has denied that Ms. Butina ever acted as a Russian agent, though it has also organized a social media campaign supporting her release.
And President Vladimir V. Putin, during his year-end news conference, said he was puzzled by her detention. “I do not understand why they put her there in the first place,” he said. “There were simply no grounds for it.”
He added, “We will not arrest innocent people simply to exchange them for someone else later on.”