By Michelle Nichols

NEW YORK, Feb 2 (Reuters) - The party of Myanmar's leader Aung San Suu Kyi won a landslide victory in November and a proposal by the military, which seized power on Monday, to hold new elections "should be discouraged," a senior U.N. official told the Security Council on Tuesday.

U.N. Myanmar envoy Christine Schraner Burgener briefed the council in a private meeting after the Myanmar army detained Suu Kyi and others in response to "election fraud", handed power to military chief Min Aung Hlaing, imposed a state of emergency for one year and pledged to hold new elections.

The 15-member Security Council is negotiating a possible statement, drafted by Britain, that would condemn the coup, call for the military to respect the rule of law and human rights, and immediately release those unlawfully detained, diplomats said. Such statements have to be agreed by consensus.

"Let us be clear, the recent outcome of the election was a landslide victory for the National League for Democracy (NLD)," Schraner Burgener told the 15-member council, according to excerpts of her remarks seen by Reuters.

"The declaration of the Statement of Emergency and the arrest of civilian leadership are unconstitutional and illegal," she said. "The military's proposal to hold elections again should be discouraged."

The United Nations also raised fears on Monday that the coup in Myanmar will worsen the plight of some 600,000 Rohingya Muslims still in the country.

A 2017 military crackdown in Myanmar's Rakhine State sent more than 700,000 Rohingya Muslims fleeing into Bangladesh, where they are still stranded in refugee camps. U.N. Secretary-General Antonio Guterres and Western states accused the Myanmar military of ethnic cleansing, which it denied.

"At this point in time, we must ensure the protection of people of Myanmar and their fundamental rights. We must do everything to prevent violence from breaking out," Schraner Burgener said. (Reporting by Michelle Nichols Editing by Alistair Bell)