"We are calling on Washington to issue visas to our delegation and journalists without delay. Failure to issue these is a violation of the obligations of the United States as the host country of the UN headquarters, which impedes the proper functioning of the organization," Antonov said in a statement.
The ambassador added that "an unclear situation is developing around the minister's special flight."
"The US authorities have not yet approved the arrival of the plane. We expect the Americans to promptly issue permission for the overflight of the aircraft without any conditions or restrictions," Antonov said.
He noted that the uncertainty remains even though UN events are just days away.