China said on Monday it had lodged a complaint with the United States over a US spy plane that flew over parts of the disputed South China Sea in a diplomatic row that has fuelled tension between the world's two largest economies.
Friction in the region has grown over China's land reclamation in the Spratly islands. China last week said it was "strongly dissatisfied" after a US spy plane flew over areas near the reefs, with both sides accusing each other of stoking instability.
Chinese foreign ministry spokesperson Hua Chunying said on Monday China had lodged a complaint and that it opposed "provocative behaviour" by the United States.
"We urge the US to correct its error, remain rational and stop all irresponsible words and deeds," she said. "Freedom of navigation and overflight by no means mean that foreign countries' warships and military aircraft can ignore the legitimate rights of other countries as well as the safety of aviation and navigation."
China had noted "ear-piercing voices" from many in the US about China's construction on the islands and reefs.
The nationalist Global Times, a tabloid owned by the ruling Communist Party's official newspaper, the People's Daily, said war was "inevitable" between China and the United States unless Washington stopped demanding Beijing halt the building of artificial islands in the disputed waterway.
It said China was determined to finish its construction work, calling it the country's "most important bottom line".
Such commentaries are not official policy statements, but are sometimes read as a reflection of government thinking.
China claims most of the South China Sea, through which $5 trillion in ship-borne trade passes every year. The Philippines, Vietnam, Malaysia, Taiwan and Brunei have overlapping claims.
The United States has routinely called on all claimants to halt reclamation in the Spratlys, but accuses China of carrying out work on a scale that far outstrips any other country.
Washington has also vowed to keep up air and sea patrols in the South China Sea amid concerns among security experts that China might impose air and sea restrictions in the Spratlys once it completes work on its seven artificial islands.
China has said it has every right to set up an Air Defence Identification Zone in the South China Sea but that current conditions did not warrant one.
The Global Times said "risks are still under control" if Washington takes into account China's peaceful rise.
"We do not want a military conflict with the United States, but if it were to come, we have to accept it," the newspaper said.
China's state media has stepped up its rhetoric against the United States, warning that the row over the South China Sea could hurt broader relations. But there appears to be little popular anger among the Chinese population so far, judging from sentiment expressed on Weibo, China's version of Twitter.