Violence in Myanmar is worsening, and the running of the state is at risk of coming to a standstill in the absence of a collective international response to the country's coup, the UN Security Council has reportedly heard from the UN special envoy to the country.
The details from the private meeting were relayed to Reuters by diplomats who attended.
UN special envoy Christine Schraner Burgener briefed the 15-member council from Thailand, where she has been meeting with regional leaders.
Schraner Burgener still hoped to travel to Myanmar - where the 1 February military coup ousted an elected government led by Aung San Suu Kyi - but the military was yet to approve a visit.
Pro-democracy protests have taken place in cities and towns across the country since the coup.
"The general administration of the state could risk coming to a standstill as the pro-democracy movement continues in spite of the ongoing use of lethal force, arbitrary arrests and torture as part of the military's repression," Schraner Burgener said, according to diplomats.
The Assistance Association for Political Prisoners advocacy group said more than 3400 people had been detained for opposing the coup, and security forces had killed at least 759 protesters. Reuters was unable to confirm the casualty toll.
The military, which ruled for almost 50 years until launching a tentative reform process a decade ago, has acknowledged the death of some protesters, saying they were killed after they initiated violence.
Schraner Burgener told diplomats that reports of a continuing crackdown risked undermining momentum toward ending the crisis following a meeting last Saturday between the junta leader, Senior General Min Aung Hlain and the 10-member Association of Southeast Asian Nations (ASEAN).
Britain's deputy UN ambassador James Roscoe said after the Security Council briefing on Friday that it was "deeply concerning" that Min Aung Hlaing did not plan to immediately implement ASEAN's recommended steps to end the crisis.
"It's really vital that the military junta do follow the ASEAN consensus, as opposed to their own roadmap. And it was clear in the discussion that the (Security) council felt that the council had a continuing role in maintaining pressure to that end," Roscoe told reporters.
Schraner Burgener said there were concerning reports that civilians, mostly students from the urban areas, were being trained how to use weapons by ethnic armed organisations.
"In the absence of a collective international response, there has been a rise in violence and reported use of improvised explosive devices. Calls for maximum restraint by all sides have been met with responses from some protesters asking who can blame them for their self-defence," she said, according to diplomats.