Thai Prime Minister Yingluck Shinawatra says flood barriers on the Chao Phraya river are holding and are likely to protect Bangkok and its 12 million residents from the country's worst and deadliest flooding in decades.

Ms. Yingluck spoke Sunday, as flood experts said the crest of floodwaters flowing southward from rain-saturated northern Thailand had cleared the capital without major damage and entered the Gulf of Thailand. Authorities also said floodwaters that devastated provinces north of Bangkok have begun to recede and said the city will not encounter high sea tides until later this month.

More than two months of relentless monsoon rains have inundated two-thirds of the Southeast Asian nation, killing nearly 300 people and inflicting an estimated $5 billion in property losses. North of the capital, much of the ancient temple city of Ayutthaya remained under water, driving residents on Saturday to safety on rooftops.

A team of U.S. Marines began aerial surveys of the region on Sunday, to help assess damage and determine how the U.S. government might assist local recovery efforts in Thailand's worst-hit areas.

Abnormal rainfall that began in late July has also killed 100 more people in nearby Cambodia and Vietnam.

Officials in Vietnam said last week that most of Vietnam's more than 40 dead were children unable to escape the reach of the Mekong river's raging floodwaters. The flooding submerged more than 70,000 homes, blocked roadways and forced the closure of hundreds of schools.