WASHINGTON — The US objected Wednesday to Iran’s anticipated selection of a former hostage-taker at the American Embassy in Tehran as its newest ambassador to the United Nations. But the Obama administration stopped short of saying it would refuse him a visa to enter the United States.

State Department deputy spokeswoman Marie Harf called the potential nomination of Hamid Aboutalebi “extremely troubling” and said the US has raised its concerns with Tehran. Lawmakers in Congress who usually disagree on everything — ranging from liberal New York Democrat Sen. Chuck Schumer and conservative Texas Republican Sen. Ted Cruz — have demanded that Aboutalebi be barred from living and working in the United States.

But Harf noted that except in limited cases, the US is generally obligated to admit the chosen representatives of member states to UN headquarters in New York.

“We’re taking a close look at the case now, and we’ve raised our serious concerns about this possible nomination with the government of Iran,” Harf told reporters. She added: “But we do take our obligations as host nation for the United Nations very seriously.”

Hamid Babaei, a spokesman for Iran’s Mission to the United Nations, had no comment Tuesday on his government’s choice for ambassador.

Aboutalebi was a member of a Muslim student group that stormed the US Embassy in Tehran in 1979 and held 52 Americans hostage for 444 days. He reportedly has insisted that his involvement in the group — Muslim Students Following the Imam’s Line — was limited to translation and negotiation.

Hamid Aboutalebi (photo credit: screenshot via YouTube)

Hamid Aboutalebi (photo credit: screenshot via YouTube)

But lawmakers have derided Aboutalebi as a terrorist and a key conspirator in the hostage crisis, and warned that his nomination would escalate tensions in already delicate negotiations aimed at curbing Tehran’s nuclear program.

In a letter Wednesday to Secretary of State John Kerry, Schumer said Aboutalebi’s association with the student group should make him ineligible for a visa or diplomatic immunity in the US.

“This man has no place in the diplomatic process,” Schumer said in a separate statement. “Iran’s attempt to appoint Mr. Aboutalebi is a slap in the face to the Americans that were abducted, and their families. It reveals a disdain for the diplomatic process and we should push back in kind.”

Earlier this week, Cruz questioned the wisdom of negotiating with the Iranian government in light of what he called its “deliberately insulting and contemptuous” choice for UN ambassador. The nuclear negotiations are set to resume next week in Vienna.

Harf insisted the nuclear talks and the UN envoy were separate issues, even as she noted Washington’s ongoing concerns with Iran on multiple fronts.

“On the nuclear issue, they have upheld their commitments,” Harf said. “We hope they will continue to.”

At a US Senate hearing Wednesday, Treasury Under Secretary David Cohen claimed that companies were not hurrying to do business with Iran now that sanctions have been eased.

“We have not seen companies anywhere — Europe, the Gulf, Asia — trying to take advantage of this … narrow opening, the quite limited suspensions of the sanctions to get into the Iranian market, enter into business deals that would otherwise be sanctionable,” David Cohen said, according to Reuters.

Cohen noted that the preliminary estimate of what sanctions relief would bring Tehran — 6-7 billion dollars — was holding.

“Nothing that we have seen leads us to question that estimate. If anything, that estimate is probably on the high side,” he said.