not a single member of the 56-member Russian advance team and delegation headed by Foreign Minister Sergey Lavrov has received a U.S. entry visa

The [RF permanent] ambassador [to the UN Vassily Nebenzia] stressed that the United States, as the host country of the United Nations, is legally required to issue visas, adding that application to attend the high-level U.N. meetings starting Sept. 19 had been submitted to the U.S. Embassy in Moscow.
[...]
The Russian ambassador quoted from the 1947 agreement between the United Nations and the United States which states that "visas shall be granted without charge and as promptly as possible" and that this "shall be applicable irrespective of the relations existing between the governments of the persons referred to ... and the government of the United States."