China has a range of options to counter an escalating US military challenge to its territorial claims in the South China Sea, ranging from dispatching more warships to conducting military drills - and, if necessary, ramming the ships, mainland analysts say. Beside warnings, the PLA could deploy warships and military aircraft to expel the destroyer USS Lassen if it keeps patrolling within the 12-nautical-mile limit of Chinese-controlled islands in the region, said Li Jie , a naval expert based in Beijing. Citing an incident between the US and Soviet navies in 1988, "China could also initiate a measured collision at the most critical moment if the US warship refuses to leave after being expelled," Li said. READ MORE: Warships sent, US ambassador called in as China bolsters Navy presence in disputed Spratly islands On February 12 of that year, the cruiser USS Yorktown and the destroyer Caron entered the seven nautical mile limit of the former USSR naval base at Sevastopol, a Black Sea port on the Crimean Peninsula that itself is now the centre of a territorial dispute between Russia and Ukraine. After several warnings were ignored, the Soviet frigate Bezzavetny was sent to ram both US warships, forcing them to leave, which was seen as a move to push the US navy to comply with international maritime law. Sun Zhe, the director of the Centre for US-China Relations at Tsinghua University, said once China deployed warships or aircraft to the waters, tensions in the South China Sea would escalate. "[China] may resort to locking its radar on the US ship, or declare a drill in the area or use military or even civilian vessels to expel the US warship," Sun said, adding that any escalation would become "a test" for both Beijing and Washington. But Li stressed China would still "try peaceful means before resorting to force". Li said that even when a PLA fighter jet collided with a US EP-3 spy plane off the coast of Hainan in April 2001, killing Chinese pilot Wang Wei, neither side resorted to military means to solve the problem. [China] may resort to locking its radar on the US ship, or declare a drill in the area or use military or even civilian vessels to expel the US warship Sun Zhe, the director of the Centre for US-China Relations at Tsinghua University The incident caused a wave of public anger in China. But China played down the issue after the US said it was "very sorry" about the death of Wang, whose body was never recovered, while requesting the return of the US crew and aircraft. In 2009, a stand-off between the American surveillance ship USNS Impeccable and several Chinese surveillance vessels in China's exclusive economic zones in the South China Sea also prompted arguments over freedom of navigation in waters close to Chinese territory. But such crises paved the way for both sides to examine the code of conduct for unexpected encounters at sea and in the air. Shi Yinhong , a government adviser on international relations at Renmin University, said a Sino-US military confrontation over the South China Sea issue was "almost impossible". "China is still building runways on its islands and reefs, but its reclamation has stopped and the most intensified moment has passed already," Shi said. However, the two militaries had started signing a series of treaties to prevent collisions at sea following the cruiser USS Cowpens' close encounter with a PLA support ship in the South China Sea in December 2013. "The danger of a military conflict has been alleviated," Shi said.