China has hit back after the US, Philippines and Vietnam criticised new fishing rules that require foreign crews to request Chinese permission to work in much of the South China Sea, bolstering Beijing's claims over disputed waters. The US said the regulations are provocative and potentially dangerous.

Tensions in the South China Sea have risen in recent years as a result of a complex disagreements among six nations. The area boasts valuable energy resources, as well as fisheries and some of the world's busiest shipping channels. A separate territorial dispute between China and Japan, in the East China Sea, has also drawn in the US and sparked concern about regional stability.

Criticising the new rules for the South China Sea on Thursday, Jen Psaki, a US state department spokeswoman, said: "Our long-standing position has been that all concerned parties should avoid any unilateral action that raises tensions and undermines the prospects for a diplomatic or other peaceful resolution of differences."

But on Friday Beijing's foreign ministry spokeswoman Hua Chunying said the disagreement was "not a problem of regulation … but a problem of the mentality of the reader".

The new rules were introduced by China's southern Hainan province on 1 January. They require foreign fishing crews to obtain permits before working in much of the South China Sea. They are based on a Chinese law passed in 2004.

Chunying said the government was acting according to international and domestic law, adding: "For more than 30 years, China's relevant fisheries laws and regulations have been consistently implemented in a normal way, and have never caused any tension." To insist that implementation posed a threat to regional stability showed "either a lack of common sense or … ulterior motives", she added.

The Philippine department of foreign affairs said the policy "escalates tensions, unnecessarily complicates the situation in the South China Sea and threatens the peace and stability of the region." It added it had asked China for clarification and said the regulation violated international law.

Vietnam's foreign ministry spokesman Luong Thanh Nghi said in a statement that Hanoi had indisputable sovereignty over the Spratly and Paracel Islands, and that "all foreign activities in these areas without Vietnamese acceptance are illegal and invalid".

Huang Jing, a north Asia security expert at Singapore's Lee Kuan Yew school for public policy, said there were questions about how China would enforce the rule and precisely which areas were covered. "If there's some fishing boat from the Philippines or Malaysia or especially Vietnam – where the fishing industry accounts for a substantial part of GDP – by what means will China enforce the rules and will this lead to conflict? That's the issue," he said.

He added: "As China's capabilities become stronger and stronger, its behaviour seems to have become more and more assertive, especially in the South China Sea."

Fishing crews have often been caught in the territorial wrangling. In March last year, Hanoi accused China of shooting at a Vietnamese fishing boat in the area and setting fire to its cabin. In May, a Taiwanese fisherman was shot dead by Philippines coastguards in waters claimed by both countries. Wu Shicun, the former head of Hainan's foreign affairs office, now leading a thinktank advising the government on the area, told Reuters news agency that offending foreign fishing vessels would be expelled from waters around Hainan and the disputed Paracel Islands.

"If we can't expel them, then we'll go on board to make checks to see whether there's any illegal fishing," said Wu, president of the National Institute for South China Sea Studies. "We'll drag you back to be handled, confiscate fishing gear, detain the vessel and fine [you]. The most serious fine is 500,000 yuan [£50,000]."

While the US is not directly involved in the South China Sea dispute, Jin Canrong, of Renmin University's School of International Studies, said it was concerned about its overall freedom of navigation.

The US also took action when China announced the creation of an air defence identification zone over the East China Sea late last year, including airspace over disputed islands known as the Diaoyu to China and Senkaku to Japan. It flew two unarmed B52s through the zone.

Jin said: "Another concern of the US is that in the past, the US and its partners set the norms and rules in Asia and they are afraid [of whether] China tries to set norms of its own. China has risen so fast and is so big. It's natural for the US to have some concern."