Myanmar's has launched what it called a "people's defensive war" against the military junta, urging citizens across the country to revolt.
In a video address posted on his official Facebook page on Tuesday, acting president of the National Unity Government (NUG) Duwa Lashi La called on militias and ethnic armed organizations to attack forces.
"With the responsibility to protect life and properties of the people, the National Unity Government ... launched a people's defensive war against the military junta," Duwa Lashi La said.
The NUG is a group of ousted lawmakers, opponents of the coup and representatives of ethnic minority groups that seeks to gain recognition as the legitimate government of Myanmar. It operates undercover or through members based abroad.
"As this is a public revolution, all the citizens within entire Myanmar, revolt against the rule of the military terrorists led by Min Aung Hlaing in every corner of the country," said Duwa Lashi La, as he urged civil servants to leave government positions.
Min Aung Hlaing is Myanmar's military chief who on February 1, overthrowing the elected government of National League for Democracy party. Last month, the junta leader prime minister and installed a caretaker government.
Over the past eight months, the military has waged a bloody crackdown on nationwide protests and opposition to its rule. More than 1,000 people have been killed by security forces and more than 7,800 arrested, according to advocacy group Assistance Association for Political Prisoners.
have formed to defend towns and villages and carry out guerrilla-style attacks on military forces. Thousands of people have been displaced in fighting between Myanmar soldiers and these militia groups, particularly in the ethnic minority regions.
"We have to initiate a nationwide uprising in every village, town and city, in the entire country at the same time," said Duwa Lashi La. "We will remove Min Aung Hlaing and uproot dictatorship from Myanmar for good and be able to establish a peaceful federal democratic union that fully safeguards equality and is long-aspired by all the citizens."
In his speech, Duwa Lashi La ordered ethnic armed groups to "immediately attack Min Aung Hlaing and the military council," urging them to "fully control your lands."
He also called on personnel in the police, military and military-appointed government workers to join the resistance.
"This revolution is a just revolution. A necessary revolution for building a peaceful country and an establishment of a federal union," he said.
CNN has reached out to Myanmar's military for comment.
Maj. Gen. Nerdah Bo Mya, commander of the ethnic armed group Karen National Defense Organization, which operates in southeastern Karen state, said it supports the NUG's announcement.
"All the ethnic armed groups should coordinate and work together to fight and support," he told CNN. "Today is the beginning of the downfall of the military regime in Burma. D-Day is coming to Burma."
International efforts to stop the violence in Myanmar have so far failed.
Western governments, including the United States, United Kingdom and European Union, have imposed sanctions on the military junta and the (ASEAN) appointed a special envoy to Myanmar who is negotiating a visit to the country, to Reuters.
The NUG's declaration comes two weeks before the start of the UN General Assembly in New York on September 21 and an expected decision on who will fill the Myanmar representative to the UN's seat: a member of the military council, or NUG.
"The NUG will be hoping to demonstrate that the regime does not have 'effective control' of Myanmar to undermine its chances of being seated at the UN," said Richard Horsey, senior adviser on Myanmar to the International Crisis Group. "Armed resistance to the coup has been intense for some time, but the NUG is looking to put its imprimatur on these efforts and further boost them."
The extent of the NUG's control and influence over the various people's resistance groups is unclear, but there remains widespread public opposition in the country to the coup.
"With a population determined to resist, and a regime determined to hang on at all costs, violent confrontation is likely to continue," Horsey said. "This also makes ASEAN's efforts look all the more out of touch, with its special envoy yet to visit the country, and calling just three days ago for a ceasefire."