Prime Minister Prayut Chan-o-cha has called on Thais to maintain unity and goodwill towards each other as His Majesty the King's coronation will take place soon.

The prime minister also said he hoped a general election expected on Feb 24 and Thailand taking up the Asean chairmanship on Jan 1 next year would proceed peacefully.

Gen Prayut was speaking at a ceremony to unveil the Lam Saphung Dam construction project in Chaiyaphum's Nong Bua Daeng district on Monday.

"His Majesty's coronation will take place soon. The King is a major pillar of the country. I know Thais are loyal to the monarchy. Please give a helping hand," Gen Prayut said.

He said the King will make the decision about when the coronation takes place.

"When the King sets the date of the coronation, we need to be sure peace and order prevail," Gen Prayut said.

"His Majesty the King has continued what King Rama IX initiated. His Majesty always tells me and the government to try our best to take care of the people, fulfil their needs swiftly, solve their problems and explain to them to make sure they understand," Gen Prayut said.

Gen Prayut previously said in June that the King's coronation was expected to be held before the general election in February.

Addressing Thailand's role as Asean chair next year, Gen Prayut said the country will host major meetings of the regional grouping and he wanted them to proceed without any trouble.

The last time Thailand held its turn at Asean's helm was from July 2008 to December 2009.

Gen Prayut stressed the need to avoid a repeat of the fiasco in April of 2009 when protesters led by the red-shirt United Front for Democracy against Dictatorship disrupted and laid siege to the Asean summit in Pattaya and forced the hurried evacuation of regional leaders.

"I ask for two things. A peaceful election and a peaceful Asean chairmanship for Thailand. Don't let anyone disrupt it [the Asean summit] again," Gen Prayut said.