BEIJING, May 25 -- China has lodged solemn representations with the United Statesfollowing a U.S. military jet's reconnaissance in the South China Sea, a Foreign Ministry spokesperson said Monday.

"The close reconnaissance conducted by the U.S. military aircraft of China's maritime features is highly likely to cause miscalculation and untoward incidents in the waters and airspace, and is utterly dangerous and irresponsible. China firmly opposes America's provocation,"spokesperson Hua Chunying said at a daily press briefing.

Hua's comments came after some U.S. officials were reported saying that equitable resolution of disputes and freedom of navigation are being challenged by Chinese activities in the South China Sea.

For a long period of time, there has been no problem concerning freedom of navigation and over-flight in the South China Sea, which all countries are entitled to under the international law, Hua said. "Nor will there be any in the future."

China has always valued and safeguarded the freedom and safety of navigation and over-flight in the South China Sea, Hua said.

But the freedom of navigation and over-flight in no way means that foreign military vessels or aircraft can violate the international law and disregard the legitimate rights and the safety of over-flight and navigation of other countries, she said.

Hua said China's determination to safeguard national sovereignty and territorial integrity was "as firm as a rock."

She urged the United States to correct its mistake, stay rational and stop irresponsible words and actions.

In response to a question concerning U.S. officials' comments on the code of conduct in the South China Sea (COC), Hua said China and ASEANcountries are fully and effectively implementing the Declaration on the Conduct of Parties in the South China Sea (DOC).

Under this framework, consultations on the COC are progressing steadily and all parties are making efforts to seal the COC based on consensus, she said.

As the United States is not concerned in the South China Sea, it should show full respect for China and ASEAN countries, be discreet with words and actions and create a favorable environment for consultation rather than stir up trouble, Hua said.