China media denounce US warship in South China Sea
Editorials in Chinese state media have denounced the presence of a US warship in the South China Sea, and warned that Beijing is prepared to take action.
While urging calm from both sides, media outlets also said the US was "harassing China" and that Beijing is "not frightened to fight a war".
The USS Lassen sailed in the Spratly archipelago on Tuesday as a challenge to China's claim over the islands.
China condemned the move and summoned the US ambassador in a show of protest.
China claims sovereignty over much of the South and East China seas.
The guided-missile destroyer USS Lassen breached the 12-nautical mile zone that China claims around the Subi and Mischief reefs in the Spratly archipelago.
The Global Times - which is owned by the Chinese Communist Party's newspaper People's Daily - published an English-language editorial titled "After the show, it's time for US destroyer to leave".
"We should stay calm. If we feel disgraced and utter some furious words, it will only make the US achieve its goal of irritating us," it said.
It added that Beijing should deal with Washington tactfully and "prepare for the worst".
"This can convince the White House that China, despite its unwillingness, is not frightened to fight a war with the US in the region, and is determined to safeguard its national interests and dignity."
It called on Beijing to track US warships and launch interventions if US vessels stopped in the South China Sea.
The newspaper used stronger language in an editorial in Chinese, calling for China to "hold its temper" while pouring scorn on the US.
"It can't finish the situation in Iraq or Afghanistan; it dares only to make noise against Russia; it has failed to achieve anything in Syria; and it can't really take down Pyongyang. China really hasn't provoked it, but the US truly is only a 'paper tiger'," it said.
Xinhua state news agency similarly slammed "the lame-duck Obama administration" for trying to reassure allies in Asia "at a time when its so-called Asia Rebalance policy falters", and warned that China "will take whatever means at whatever cost to safeguard its sovereign interests".
People's Daily carried a commentary in Chinese by Su Xiaohui, the deputy head of the China Institute of International Studies, who noted that South East Asian countries "did not want to see the South China Sea's peace broken".
"Those who upset plans will be met with suspicion and condemnation," he wrote.
Under maritime laws the 12-nautical mile zone cannot be claimed for features that were submerged and raised through human intervention.
The reefs, which were submerged, were turned into islands by China by a massive dredging project which began in late 2013.
China says its work is legal and for civilian purposes, but Washington believes Beijing is constructing military facilities to reinforce its disputed claim to most of the region - a major shipping zone.
The USS Lassen operation was part of America's Freedom of Navigation programme to challenge "excessive claims" in the world's oceans and airspace, and was welcomed by several countries in the region, including the Philippines and Japan.
Other countries in South East Asia have competing claims for the Spratly Islands, Paracel Islands and Scarborough Shoal, which are thought to have resource-rich waters around them.