Thailand's military government says it will hold a general election in November 2018 after repeatedly delaying the decision, citing concerns such as changes to the constitution and security issues, since taking power in a 2014 coup.

The exact election date would be announced in June 2018, Prime Minister Prayut Chan-O-Cha, the head of the ruling military government or National Council for Peace and Order, told reporters on Tuesday at Bangkok's Government House.

"Around June, we will announce the date for the next election," he said.

The decision comes more than a year after Prayut's initial promise to hold elections this year.

Thailand's last general election was in 2011.

The European Union and the United States - both key allies – had been pressuring Prayut to hold elections and lift restrictions on civil liberties imposed since his takeover.

Last year, the military pushed through a new constitution that critics said would boost military power and limit the sway of elected officials.

A divided nation

The military claimed the new charter, Thailand's 20th, will purge Thailand of corrupt civilian politicians and restore stability after nearly a decade of political turmoil including two coups.

The country has been bitterly divided ever since a 2006 coup that toppled Thaksin Shinawatra as prime minister.

Years of competing protests and instability followed. In 2014, the army seized power once more, toppling Thaksin's sister, Yingluck.

The Shinawatra clan has won all general elections since 2001, harvesting votes by promising greater wealth and opportunity to the rural poor.

But the family is loathed by an arch-royalist Bangkok elite which is backed by the military, and by southern voters who accuse the Shinawatras of corruption and populism.

Last month, Yingluck was sentenced in absentia to five years in jail after she was found guilty of negligence in a rice subsidy case.