China has urged those outside the region to respect the rules and order set by countries in the South China Sea region, in line with international law.

Foreign Ministry spokesperson Hua Chunying made the remarks in response to U.S. President Barack Obama's comments about maritime disputes in the area.

During his visit to Vietnam earlier on Tuesday, the U.S. President said "big nations should not bully smaller ones".

Hua said country size was not the key point of the issue, and neither should it be the sole or main reason to judge if a country is in the right.

She said the vital problem is whether countries involved show sincerity and determination to resolve disputes.

"We believe the countries outside the region should respect the efforts made by regional countries in safeguarding regional peace and stability, respect the regional rules and orders established based on the international law, rather than threatening sovereignty and security of coastal nations under any pretext, breaching regional rules and orders and disrupting regional peace and stability."

During the news briefing, Hua also called on the U.S. side to clarify its concept of freedom of navigation, an issue frequently raised by America.

"The U.S. side should make it clear whether it is advocating referring to the real freedom of navigation that every country enjoys under the international law, or the privilege of US warships and military planes to sail or overfly at will. If the US is talking about the real freedom of navigation, we warmly welcome and firmly support its advocation. But if it is the later, the international community will not agree."

According to Hua, China and ASEAN countries have reached a series of bilateral agreements and regional consensus on settling disputes through negotiation and consultation and jointly maintaining peace and stability in the South China Sea.

She said that this had laid an important foundation of rule and order applied to the region.

In his speech in Hanoi, the US President did note that the United States is not a claimant in current disputes in the South China Sea.