Deputy Health Minister Surawit Khonsomboon announced the premier's remarks after Ms Yingluck chaired the cabinet meeting Tuesday morning before departing for Japan.
Mr Surawit said the prime minister instructed concerned ministers to visit the haze-hit areas and quickly sort out the problem.
The minister said the health ministry was instructed to provide for the public's health, while the interior ministry was asked to facilitate funds to local authorities in handling the situation.
The premier reiterated that the Ministry of Natural Resources and Environment must take stiff measures against those who set forest afire and asked cooperation from the public to avoid any burning of croplands, Mr Surawit said. He added that the Ministry of Agriculture and Cooperatives must supervise rainmaking operations to reduce the dust particles.
"Now it cannot be judged when the situation will return to normal but all concerned agencies are speeding up their operations," the deputy minister said.
Although the prime minister gave green light for the northern provinces to declare their areas as disaster zones, the deputy minister noted that most provinces, except for Lamphun, are unwilling to do so for fear that it will negatively affect the tourism industry. They cited the need to monitor the situation closely before making such a decision.
Mr Surawit reported that the hardest-hit area is Chiang Rai's Mae Sai district with dust particles measured at over 300 microgrammes per cubic metre, a level which is above the safety standard at 120 microgrammes per cubic metres and poses health risk to human.
As of Tuesday, the deputy health minister said, the number of haze-related illness cases has risen five times with 14,000 asthma patients, 13,000 respiratory-related cases and 1,400 people reportedly suffering from eye irritation and poor vision.
Meanwhile, deputy government spokesman Pakdihan Himathongkam said the prime minister has instructed the Natural Resources Minister Preecha Rengsomboonsuk to coordinate with governors of affected provinces and report the meeting results to her directly.
The premier assigned Foreign Minister Surapong Tovichakchaikul to coordinate with Myanmar authorities as the cause of the haze siege of Thailand's upper North was due in part to burning in the neighbouring country, according to the spokesman.
Mr Pakdihan said that Deputy Prime Minister Chalerm Yoobamrung will visit Myanmar on Wednesday and hold a meeting with appropriate Myanmar agencies on the issue.