The military has weathered rounds of worldwide condemnation, justifying its power grab by alleging widespread fraud in November elections, which Suu Kyi's party had swept.
Kyaw Moe Tun had urged all countries to issue public statements strongly condemning the coup, and to refuse to recognize the military regime.
Police fired in the air and set off stun grenades as they cracked down in the neighbourhood, state media said.
State-run MRTV television said more than 470 people had been arrested. Nevertheless, at least three protesters and a policeman have been killed. Several media workers were also detained. But there is growing uncertainty about her whereabouts amid reports on an independent news website on Friday that she had been moved to an undisclosed location.
Last week, the US, Canada and the United Kingdom introduced restrictions on some of Myanmar's military generals, as anti-coup protesters called for further worldwide action.
A number of local media outlets reported that a woman had been shot at a protest in the central city of Monwya, close to Mandalay.
"We still need the strongest possible action from the global community to immediately end the military coup, to stop oppressing the innocent people, to return the state power to the people, and to restore the democracy", Kyaw Moe Tun said.
If the Myanmar junta, led by General Min Aung Hlaing, tries to seek global recognition by installing a new United Nations envoy it could set off a fight at the world body that could culminate with a vote at the General Assembly.
Police were not immediately available for comment.
"We need... the strongest possible action from the worldwide community to immediately end the military coup, to stop oppressing the innocent people, to return the state power to the people, and to restore the democracy", Kyaw Moe Tun pleaded, his voice cracking with emotion.
At the UN General Assembly, Myanmar's Ambassador Kyaw Moe Tun said he was speaking on behalf of Ms. Suu Kyi's government and appealed to the body "to use any means necessary to take action against the Myanmar military and to provide safety and securityf or the people".
Saturday saw turmoil in towns and cities across the country as police moved forcefully to stamp out the protests, firing tear gas, setting off stun grenades and shooting guns into the air.
Reuters was not immediately able to contact the army for comment.
In a further show of defiance, Kyaw Moe Tun held up three fingers, a gesture against authoritarian rule that has been adopted by anti-coup protesters in the country. The U.N. Special Rapporteur on Myanmar, Tom Andrews, called it a "remarkable act of courage".
Myanmar's generals have traditionally shrugged off diplomatic pressure.
"Woodside supports the people of Myanmar and we hope to see a peaceful journey to democracy", the company said.
The country has been shaken by a wave of demonstrations since a coup toppled civilian leader Aung San Suu Kyi on 1 February.
"We asked all parties to exercise restraint and not use violence.to avoid casualties and bloodshed", Marsudi said in a virtual news conference.
According to the association, 771 people have been arrested, charged or sentenced at one point in relation to the coup, and 689 are being detained or sought for arrest.
Ms. Suu Kyi, the daughter of Myanmar's independence hero, spent almost 15 years under house arrest under previous juntas.
The army has promised an election, but has not given a date.
China's U.N. Ambassador Zhang Jun, whose neighboring country has invested billions of dollars in Myanmar and is its biggest trading partner, called on all parties to handle differences through dialogue "under the constitutional and legal framework", avoid violence, "and continue to promote the domestic democratic transformation process in an orderly manner". The junta has said it will rule for a year under a state of emergency and then hold new polls.
Indonesia has taken the lead but coup opponents fear the effort could legitimise the junta and what they see as its bid to annul the November election.