Australian energy giant Woodside has announced it is withdrawing from Myanmar, almost one year after the military seized power in an illegal coup.

The company has been under intense pressure over its involvement in a major deepwater gas development which activists said would pour millions of dollars into the pockets of the military junta.

While the company put its operations in Myanmar on hold around 11 months ago, it will now begin to withdraw from its remaining exploration contracts with the state-held Myanmar Oil and Gas Enterprise (MOGE).

In a statement to the ASX, Woodside said there was "no longer a viable option" for it to continue its activities in Myanmar.

In a separate statement on its website the company said: "Woodside condemns human rights violations. We have watched with growing concern since the events of 1 February 2021."

"Woodside supports the people of Myanmar and we hope to see a peaceful journey to democracy."

The announcement comes only days after US energy giant Chevron and French company TotalEnergies announced they would pull out of the country.

There has also been growing speculation that the US government may soon directly target MOGE and other state-owned Myanmar companies with sanctions.

The decision will deliver a $195 million hit to Woodside's 2021 profits, on top of almost $100 million it has already spent on exploration for another gas project in Myanmar.

Woodside's announcement has been welcomed by activists in both Myanmar and Australia.

"This decision sends a signal to all remaining ASX and Australian mining, oil and gas companies such as PanAust, Roc Oil, Tap Oil and Access Asia Mining to give up all exploration licences and rule out financing the Myanmar military's regime of terror," said Clancy Moore from anti-corruption NGO Publish What You Pay Australia.

The group estimates that offshore gas revenues provide around half the military's foreign currency and feed around $2.1 billion into its coffers every year.

Earlier this month Myanmar's ousted civilian leader Aung San Suu Kyi was sentenced to four more years in jail by a military tribunal.

The military junta has also escalated violence against civilians in recent months, while conflicts with armed ethnic groups have intensified.

Elaine Pearson from Human Rights Watch said the withdrawal of energy companies would "only be gestures" without targeted sanctions from the international community, including Australia, the European Union and the United States.

"Myanmar's military will continue to collect massive revenues from natural gas and other extractive sectors unless new targeted sanctions block foreign currency payments, because other companies will take over their operations," she said.