UNITED NATIONS - The United States has given Russian Foreign Minister Sergei Lavrov a visa to travel to New York for the United Nations' annual gathering of world leaders next week with half the delegation Moscow requested, a Russian diplomatic source said on Tuesday.

Moscow had asked Washington for 56 visas, according to a Sept 2 letter to UN Secretary-General Antonio Guterres from Russia's UN Ambassador Vassily Nebenzia.

The Russian diplomatic source said on Tuesday the US had approved 24 visas.

Nebenzia had also noted in his letter that the flight crew for Lavrov's plane had not received visas. It was not immediately clear if Washington had granted visas for the Russian flight crew or if Lavrov would be expected to fly commercial airlines to New York.

The US State Department did not immediately respond to a request for comment.

The high-level meeting of the UN General Assembly begins on Sept 20.

Under the 1947 UN "headquarters agreement," the US is generally required to allow access to the UN for foreign diplomats. But Washington says it can deny visas for security, terrorism and foreign policy reasons.

The UN said earlier this month that it was speaking with the US about the issue of Russian visas.

The relationship between the US and Russia has ruptured since Moscow invaded neighbouring Ukraine in February.

Russia calls its actions in Ukraine "a special military operation." The Kremlin on Tuesday said the US was "violating its obligations" by not issuing visas to Russia's full delegation and said it would hold the UN and the US to account over the situation.

The US said earlier this month it takes its UN host country obligations seriously and that visa records are confidential under US law, so it could not comment on individual cases. REUTERS