Myanmar's dueling governments each now claim to represent the country at the United Nations, making it likely that member states will have to step in and decide whose ambassador to recognize.
"I can confirm we received two letters," U.N. Spokesman Stephane Dujarric told reporters. "They are currently under review."
He said a letter was received Monday from Kyaw Moe Tun, the ambassador of Myanmar who took up his post in October, confirming he is still the U.N. representative. A second communication was received Tuesday from Myanmar's Foreign Ministry, informing the secretary-general that Tin Maung Naing, the deputy ambassador at the U.N. mission, has been appointed as Charge d'Affaires as of February 28.
"Let's be honest here, we are in a very unique situation we have not seen in a long time," Dujarric said. "We are trying to sort through all the legal protocol and other implications."
At a meeting Friday of the General Assembly, Myanmar Ambassador Kyaw Moe Tun made an emotional appeal to the international community, urging nations to reject the February 1 military coup, and "to use any means necessary" to protect the people. State television announced the next day that he had been fired.
FILE - Myanmar's ambassador to the U.N., Kyaw Moe Tun, holds up three fingers to the General Assembly, where he pleaded for international action in overturning the military coup in his country, as seen in this still image taken Feb. 26, 2021.
In his letter to the president of the General Assembly and copied to the office of the U.N. secretary-general, Kyaw Moe Tun said he was appointed by President U Win Myint, "the lawfully elected President of Myanmar" and by Foreign Minister Aung San Suu Kyi.
Both the president and Suu Kyi are among dozens of officials who have been detained during the military's power grab.
Popular protests across the country opposing the military's coup have grown increasingly violent and deadly. Diplomats say the U.N. Security Council will discuss the situation on Friday.
"The perpetrators of the unlawful coup against the democratic government of Myanmar have no authority to countermand the legitimate authority of the President of my country," Kyaw Moe Tun's letter states. "I wish therefore to confirm to you that I remain Myanmar's Permanent Representative to the United Nations."
The communication from the Foreign Ministry is unsigned, but it has the official seal and announces that the "State Administration Council of the Republic of the Union of Myanmar terminated the duties and responsibilities of Ambassador U Kyaw Moe Tun" on February 27 - the day after his speech denouncing the coup.
"In this regard, the Ministry would like to request the Executive Office of the Secretary General of the United Nations to accept the decision made by the State Administration Council of Myanmar," the letter read.
Traditionally, if there is a dispute over who is the accredited representative of a country, the U.N. credentials committee, made up of nine member states, would review the matter and make a recommendation.
"After that it would come to the General Assembly, as a whole, to consider the recommendation from the credentials committee," said Brenden Varma, spokesman for the president of the General Assembly.
"We have not seen any official evidence - or request that he be removed, and for the time being he is the representative of the Myanmar government," U.S. Ambassador Linda Thomas-Greenfield said Monday when asked at a news conference who the U.S. recognizes as representing Myanmar at the United Nations.
U.N. Secretary-General Antonio Guterres has repeatedly called on the military to reverse its actions and respect the will of the people as expressed in November's election - which saw the National League for Democracy party secure 82% of the vote.
U.N. Special Envoy for Myanmar Christine Schraner Burgener urged the international community Friday not to "lend legitimacy or recognition" to the military regime.
She said she was deeply troubled by the ongoing arrests of political leaders, including NLD legislators, government officials, civil society actors and journalists, and she condemned the use of lethal force against peaceful protesters and the rising deaths as "unacceptable."