China holds a responsible attitude when developing the Lancang River and highly values ecological protection, said Foreign Ministry spokesman Hong Lei on Thursday.

The Lancang River [File photo]

"In the process of development, China fully takes into considerations the lower stream countries," Hong told reporters at a regular news briefing.

The spokesman was affirming comments by Cambodian Prime Minister Hun Sen, who reiterated on Wednesday that disasters and floods in his country are not caused by Chinese dams, but are triggered instead by global climate change.

The prime minister told environmentalists not to be "too extreme."

The 4,350-km Mekong River - known as the Lancang River in China - flows through China's Tibetan Plateau, Yunnan province, Myanmar, Laos, Thailand, Cambodia and Vietnam.

"So please don't be too extreme don't say hydropower dams" are the cause of the situation, Hun Sen told reporters after a series of summits held among government leaders of Cambodia, Laos, Myanmar, Vietnam and Thailand.

To do so, he added, would be a "mistake."

"I do not defend China and I also do not defend Laos that built hydropower dam, I also do not defend the hydropower dam that the Cambodian government (is) allowed to build - but you should think when strong rains come, they cause floods, and when there is no rain drought."

Water flowing from China only contributes to 20 percent of the Mekong's water volume that reaches the river basin nations, while the remaining 80 percent is fed from water sources in Laos.

More than 60 million people rely in some way on the river, which is the world's largest inland fishery, producing an estimated catch of 3.9 million tons annually, according to the Mekong River Commission (MRC).

In April when Hun Sen attended the first MRC Summit in Hua Hin, Thailand, the Cambodian prime minister said his statements were to "provide justice for China."

"They (some countries) are blaming China ... while China itself is being victimized by droughts ... China's Lancang River has no water either," Hun Sen said.

China has increased its information sharing and, since March, highlighted the provision of data from two hydrological stations to lower stream nations.

In June, notably, China launched a two-week training course in flood control and disaster mitigation for 17 experts from five countries downstream of the Mekong River Basin - Laos, Myanmar, Thailand, Cambodia and Vietnam - in a bid to share experience and technology to prevent future tragedies.