Iran's Foreign Minister Mohammad Javad Zarif says US travel restrictions imposed on Iranian diplomats and their families living in New York are "basically inhuman."

"It is certainly not a friendly action. It puts the members of the mission and their families under basically inhuman conditions. But for me it's fine because I don't have any work anywhere other than the three buildings," Zarif told reporters at the United Nations on Wednesday.

The United States has restricted their travel to between the United Nations, the Iranian UN mission, the Iranian UN ambassador's residence and John F. Kennedy airport.

The United Nations on Monday expressed concerns about the curbs.

"The secretariat is aware of the restrictive travel measures imposed by the host country on personnel of the permanent mission of Iran to the UN. The secretariat is in close contact with the permanent missions of the United States and Iran to the UN regarding this matter and has conveyed its concerns to the host country,” UN deputy spokesman Farhan Haq told reporters.

Tehran says the restrictions imposed on Zarif, traveling between the United Nations and the Iranian UN mission or the Iranian UN ambassador's residence, would not affect his “work schedule.”

"Putting restrictions on his (Zarif’s) presence in some streets in New York will certainly not affect his work schedule," said Iran's Foreign Ministry Spokesman Abbas Moussavi.

Late last month, the administration of US President Donald Trump had threatened to blacklist Zarif.

The US claims it restricted Zarif’s travel “in a manner that is fully consistent” with its obligations under a 1947 agreement with the United Nations.

However, the United States is required to allow access to the United Nations for foreign diplomats under the 1947 UN "headquarters agreement.”

The restrictions come amid heightened tensions between Washington and Tehran, which started when the US unilaterally withdrew from a multilateral Iran nuclear deal clinched between the Islamic Republic and world powers in 2015, and reimposed sanctions on Iran.

Meanwhile, Zarif addressed the high-level political forum on sustainable development at the UN, during which he said the US has subjected Iranian civilians to the most brutal form of economic terrorism to achieve its political goals.

“Our people are … subjected to the most brutal form of economic terrorism, deliberately targeting innocent civilians to achieve illegitimate political objectives. The unlawful extraterritorial economic sanctions imposed on Iran by the United States, in violation of Security Council resolution 2231, represent the greatest threat to the achievement of sustainable development goals of Iran and many of our neighbors,” Zarif said. "In spite of huge impediment caused by unlawful unilateral sanctions, the Islamic Republic of Iran has made significant progress in people's empowerment and equality,” he added.

At UN conference on sustainable development, I maintained that extraterritorial sanctions the US imposed on Iran—in violation of Security Council Resolution 2231—represent the greatest threat to the achievement of sustainable development goals of Iran and many of our neighbors. — Javad Zarif (@JZarif) July 17, 2019

The US left the Iran deal, officially known as the Joint Comprehensive Plan of Action, although the agreement was endorsed by the UN Security Council in the form of Resolution 2231.

Under the deal, Iran agreed to limit certain aspects of its peaceful nuclear program in exchange for removal of nuclear-related sanctions.