Chinese President Hu Jintao has vowed to "spare no effort" to minimise the damage from a chemical spill on Russia as Beijing mulled plans to build a temporary dam to stop the slick.
"We will take all necessary and effective measures and do our utmost to minimise the pollution and reduce the damage to the Russian side," Hu told visiting Russian First Deputy Prime Minister Dmitri Medvedev.
Hu said China will deal with the issue seriously with an attitude of "being highly responsible to the two countries and the two peoples," the official Xinhua news agency quoted him as saying.
The country's top environmental agency, meanwhile, ordered a nation-wide inspection of major factories near rivers to prevent a similar disaster from happening in the future, Xinhua said.
Widespread contamination prevention efforts have been underway in China and Russia since an explosion on November 13 at a PetroChina chemical factory in the north-east Chinese province of Jilin.
The accident led to the spillage of 100 tonnes of the carcinogens benzene and nitrobenzene into the Songhua River, one of China's longest waterways and a source of water for millions. The Songhua flows into the Heilong river which is connected by waterways to a river on the Russian side.
An expert panel from China's Water Resources Ministry has travelled to the Songhua River region in Heilongjiang, which borders Russia, to investigate the feasibility of the dam, the China Daily reported.