Anti-government protesters have taken over the airport
The Thai Prime Minister Somchai Wongsawat has said he will take action to end anti-government protests in Bangkok's two main airports.
In a TV address, Mr Somchai said the police would be assisted by some military units in halting the protests.
Emergency rule has been declared around the two airports.
Thousands of passengers have been left stranded by the protest action, just the latest stand-off in a long-running political struggle gripping Thailand.
Protesters from the People's Alliance for Democracy (PAD) occupied a government complex in the capital for months.
At the start of this week said they were embarking on the "final battle" of their campaign to unseat the government, and they have vowed to resist attempts to disable their airport protests.
Mr Somchai was speaking to the nation after an emergency cabinet session was held in the city of Chiang Mai.
"It is wrong for protesters to take the entire Thai nation hostage," Mr Somchai said, according to AFP news agency.
"The government is not intending to hurt anybody... and the emergency will be temporary," he added.
The prime minister said air force and naval units would be deployed to assist police in ending the protests, which he said had caused "massive damage".
Under emergency rule, troops may be deployed, groups of more than five civilians are forbidden from forming, subject to immediate arrest, and a media blackout can be enforced.
Protesters remain resolute that their show of force will continue.
"We will not leave. We will use human shields against the police if they try to disperse us," PAD leader Suriyasai Katasila told Reuters news agency.
The BBC's Quentin Sommerville says moving the protesters will not be easy - they have shown they are willing to put up a fight, and have already called on supporters to set up roadblocks near terminal buildings.
Reports from Bangkok say tank movements there have sparked fears of an impending military coup.
On Wednesday Prime Minister Somchai Wongsawat rejected a call by army leader Gen Anupong Paochinda for new elections to end the political deadlock, saying his government was legitimate. Gen Anupong has denied any coup plot.
The protesters have occupied both Suvarnabhumi international airport and Bangkok's domestic airport, Don Mueang.
On Thursday, the Associated Press quoted Tourism Minister Weerasak Kohsurat as saying stranded passengers with "urgent needs" could be flown out of military bases around Bangkok.
The blockade comes at the height of the tourist season and threatens an industry which is one of the country's biggest earners.
September 2006: Prime Minister Thaksin Shinawatra ousted in military coup
February 2008: Samak Sundaravej sworn in as prime minister
September 2008: Protesters call for Mr Samak's resignation, saying he is a proxy for Thaksin
9 September 2008: Mr Samak dismissed for violating conflict of interest law. Somchai Wongsawat, Thaksin's brother-in-law, becomes prime minister.
October 2008: Thaksin given a two-year jail sentence for corruption in his absence
Thailand has been in political turmoil since former Prime Minister Thaksin Shinawatra was ousted in a military coup in 2006.
The PAD - a loose alliance of royalists, businessmen and the urban middle class - claim that the government is corrupt and hostile to the monarchy.
They also accuse it of being a proxy for Thaksin, who remains very popular among Thailand's rural poor.
Fresh elections at the end of 2007 failed to resolve the crisis, when a party made up of former allies of Mr Thaksin returned to power.
And since August PAD protesters have launched an all-out assault on the government, occupying government buildings and seeing former Prime Minister Samak Sundaravej forced out of office, though on an apparently unrelated matter.
BANGKOK AIRPORT CLOSED
Thousands of PAD protesters storm the airport
Protesters seize the air traffic control tower and airport closed
At least 3,000 passengers stranded for 16 hours in terminal building
Latest reports say terminal building has been evacuated