The US stance on Iran's proposed new ambassador to the United Nations is "unacceptable," Iran's Foreign Ministry spokeswoman Marzieh Afkham was quoted as saying by official IRNA news agency on Wednesday.

Hamid Abutalebi, Iran's proposed ambassador to the UN, is one of Iran's highly-skilled diplomats and once obtained US entry visa in 1990s to attend a UN meeting, Afkham said, adding that Hamid is qualified for the position.

"We've informed the government of Iran that this potential selection is not viable," White House spokesman Jay Carney said Tuesday.

The US Senate on Monday voted to deny entry of Aboutalebi for his alleged involvement in holding 52 Americans hostage in Tehran in 1979.