South China Sea heats up. China is challenging the US with risky run-ins. The Pentagon said the US military has had unsafe encounters with the Chinese military in the South China Sea in recent months. The deputy assistant secretary of defense for Southeast Asia told Fox News that there had been at least nine concerning incidents involving Chinese fighters and US aircraft over the contested waterways since mid-March. There was also an unsafe encounter involving a Chinese naval vessel and the US Navy destroyer USS Muston last month. The defense official told that some incidents were considered unsafe, though the specific details behind the incidents are unclear. Chinese escort ships sailing with a Chinese aircraft carrier group maneuvered in an unsafe and unprofessional way near the US Navy guided missile destroyer USS Muston in the South China Sea last month. Chinese media reports indicated that the Chinese Navy flotilla led by the Liaoning was conducting mock battles in the South China Sea in April. Pentagon spokesman Lieutenant Colonel Dave Eastburg said in a recent statement that the Department of Defense was concerned by increasing opportunistic activity by the PRC to coerce its neighbors and press its unlawful maritime claims in the South China Sea. The Department of Defense has said that US adversaries are trying to take advantage of the global situation but is also stressed that the US military remains ready to meet that challenge and defend US interests. In recent months, US Navy ships have conducted patrols and freedom of navigation operations in the South China Sea as well as Taiwan's straight transits and US Air Force bombers have carried out patrols in the region. US operations have continued since March. Navy vessels have conducted three freedom of navigation operations challenging China's territorial claims to the Paracel and Scrably Islands. US ships carried out multiple presence operations near a South China Sea standoff. And Navy warships, including the large amphibious assaults shift US-S America, have conducted joint drills with other nations and Air Force B-1-B Lancers have carried out two strategic bomber patrols. The US military has repeatedly criticized China's missteps which the US says caused a troubling problem that began in China and evolved into a global war. The US and Chinese militaries have had a number of unpleasant interactions over the years. The Trump administration has repeatedly criticized China's missteps which the US says caused a troubling problem that began in China and evolved into a global crisis.