China's Defence Ministry said on Thursday the country's navy would hold "routine" drills at the end of the month in international waters in the western Pacific Ocean, according to Reuters. "A formation of ships from the navy of the Chinese People's Liberation Army will hold drills in international waters in the western Pacific in the latter part of June," the ministry said in a brief statement on its website ( www.mod.gov.cn ). "These are routine drills which are planned every year. They accord with the norms of international law, and are not aimed at any country in particular, nor do they have any special aim," it added. China's growing military prowess and reach have alarmed other countries in the region, especially Japan and Taiwan, the democratically-governed island China claims as its own and has never renounced the use of force to recover. On Thursday, Vietnam accused China of harassing a ship conducting seismic surveys in the South China Sea, the second such incident in two weeks to increase tensions between the neighbouring countries with competing maritime claims. The United States, the dominant military power in the Pacific with bases in Japan and South Korea, has also looked on warily. Chinese Foreign Ministry spokesman Hong Lei repeated that China's military development was purely defensive in purpose. "There is still rather a large gap between China's weapons and those of developed countries," Hong told a regular news briefing. "China's defensive strength will not threaten any country." Beijing in March said it would boost defence spending by 12.7 percent in 2011, for a total of 601.1 billion yuan ($92.8 billion), marking a return to double-digit growth. China says it needs to upgrade its outmoded forces and that its plans are not a threat to any country, noting its defence budget is far lower than that of the United States. But President Hu Jintao has made the navy's modernisation a priority. It is upgrading its destroyers and frigates to sail further and strike harder. China could launch its first aircraft carrier this year, according to Chinese military and political sources, a year earlier than U.S. military analysts had expected, underscoring its growing maritime power and assertiveness. Japan has expressed concern in the past about Chinese warships passing close to its southern islands.