UNITED NATIONS, Sept 13 (Reuters) - The United Nations is faced with rival claims to Myanmar"s seat at the 193-member world body as the ruling junta seeks to cement its coup with international legitimacy by ousting the U.N. ambassador appointed by Aung San Suu Kyi"s elected government. Ahead of the annual gathering of world leaders at the United Nations in New York next week, there is also uncertainty over who will fill Afghanistan"s seat for the 76th General Assembly session, which no one has yet formally claimed. United Nations credentials give weight to a government. "It is ultimately about legitimacy. It is a ticket to acceptability in the international community. The alternative is pariah status," said Richard Gowan, U.N. director at the Crisis Group think tank. Myanmar"s junta has put forward military veteran Aung Thurein to be its U.N. envoy, while Suu Kyi"s Ambassador Kyaw Moe Tun has asked to renew his U.N. accreditation, despite being the target of a plot to kill or injure him over his opposition to the coup. read more U.N. spokesman Farhan Haq confirmed that the world body "has received two sets of communications concerning Myanmar"s representation at the 76th session of the General Assembly" starting on Tuesday. But a decision won"t be made quickly. Credentials are dealt with by a nine-member committee appointed at the start of each General Assembly session. It routinely includes Russia, China and the United States and traditionally does not meet until October or November. The U.N. committee considers the credentials of all 193-members and submits a report for General Assembly approval before the end of the year. The committee and General Assembly usually operate by consensus on credentials, diplomats said. Until a decision is made on Myanmar"s accreditation, Suu Kyi"s Ambassador Kyaw Moe Tun will remain in the seat, according to the General Assembly rules. While the junta requested that its foreign minister Wunna Maung Lwin lead a delegation to the high-level U.N. gathering it will likely be Kyaw Moe Tun who addresses the world body on Sept. 27, diplomats said. The Myanmar military toppled Suu Kyi"s government on Feb. 1, detaining her and other leaders. Security forces have killed hundreds of protesters since the coup and a shadow government last week declared a nationwide uprising against the junta. AFGHANISTAN SEAT Comparisons have been drawn between the situation in Myanmar and Afghanistan, where the Taliban seized power last month. However, diplomats said that unlike in Myanmar the ousted government crumbled after President Ashraf Ghani fled. "The situations are comparable in a way. Let"s see," Russian U.N. Ambassador Vassily Nebenzia told reporters on Thursday when asked about the U.N. credentials of Afghanistan and Myanmar, noting that it would be up to the committee to discuss. Haq said that no requests for credentials for Afghanistan"s U.N. seat for the 76th session had yet been received from either the current U.N. Ambassador Ghulam Isaczai, who was appointed by Ghani, or the Taliban. When the Taliban last ruled between 1996 and 2001 the ambassador of the Afghan government they ousted remained the U.N. representative after the credentials committee deferred its decision on rival claims to the seat. The decision was postponed "on the understanding that the current representatives of Afghanistan accredited to the United Nations would continue to participate in the work of the General Assembly," according to the committee report. The committee also appears to have the option of leaving a seat empty. In 1997 it deferred a decision on rival claims to represent Cambodia and left the seat empty for that session. A coalition government was formed in Cambodia the following year, which then filled the seat.