Tehran: Iran’s foreign ministry said on Tuesday that it’s still waiting for Washington’s formal response on Tehran’s pick for its new UN envoy, a day after American lawmakers voted to bar the diplomat from entering the country.

American officials have objected to the selection of the diplomat, Hamed Aboutalebi, because of his alleged participation in a Muslim student group that held 52 Americans hostage for 444 days in the 1979 seizure of the US Embassy in Tehran. The Obama administration has stopped short of saying it would refuse him a visa.

Iranian foreign ministry spokeswoman Marzieh Afkham said Tehran does not consider the matter fully decided for now.

“We think the process is running its diplomatic course and until we receive a formal response from official channels, we do not consider the matter finished. We only recognise a formal response from official and diplomatic channels,” she said.

Afkham said the ministry had communicated with “relevant US officials” following moderate President Hassan Rouhani’s nomination of Aboutalebi.

“We continue our follow-up through diplomatic channels,” she said.

The US Senate on Monday approved a bill that would bar Aboutalebi from entering the United States. Prospects for the bill in the House are unclear, though it is expected to have strong support.

Tuesday’s remarks were Iran’s first public statement about the matter since American officials raised objections to Aboutalebi’s nomination. While she did not mention him by name, Afkham’s reference to him was clear as she defended his credentials.

“In our opinion, we have introduced our ambassador. He is an ambassador with good, clear and positive diplomatic experience in various European countries and in Australia,” she said.

Aboutalebi, who worked as Iran’s ambassador to Belgium, the European Union, Italy and Australia, reportedly has insisted that his involvement in the group Muslim Students Following the Imam’s Line was limited to translation and negotiation.

The 444-day hostage crisis was a key moment in the lives of many senior political figures in Iran and led to diplomatic relations being cut between Washington and Tehran.

Some Iranians who were closely linked to the US Embassy seizure later moderated their views toward outreach to the US and the West. Several have held official posts in various administrations since the Islamic Revolution.

Masoumeh Ebtekar, once a spokeswoman for the student group, is now vice president in charge of environmental affairs in Rouhani’s administration.

Foreign-based Farsi websites claim that the minister of economy and financial affairs, Ali Tayebnia, was reportedly another member of the student group. He visited Washington to attend International Monetary Fund and World Bank meetings in October.