The military, which ousted Myanmar's civilian leaders and seized power in the Southeast Asian nation on February 1, had fired Kyaw Moe Tun on Saturday, a day after he spectacularly broke with the junta and pleaded with the General Assembly for help to restore democracy.

The generals appointed his deputy, Tin Maung Naing, in his place.

But on Thursday UN spokesman Stephane Dujarric said Myannmar's mission had sent a communication informing the body that Tin Maung Naing "has submitted his letter of resignation ... recalling that Mr Kyaw Moe Tun remains the permanent representative of Myanmar to the United Nations."

The move came after a stand-off which saw Kyaw Moe Tun write to the president of the UN General Assembly on Monday to insist the coup was "unlawful" and therefore the military had no authority to remove him.

"I wish therefore to confirm to you that I remain Myanmar's permanent representative to the United Nations," he added.

On Tuesday, Myanmar's foreign ministry sent a note verbale to the UN, claiming Kyaw Moe Tun had been removed.

That day Dujarric said the UN was taking a look at the two "contradictory" letters, as the body stressed the unusual nature of the situation and said UN accreditation and protocol committees would look into the issue.

They could ultimately refer it to the General Assembly for a simple majority vote.

The decision is far-reaching because it means whether or not to recognize who wields power in Myanmar.

Since Tuesday, Kyaw Moe Tun has held meetings with his counterpart from the European Union and the representative of the United States, who reiterated their support.