Beijing ? Taiwan unveiled its first formal national security policy Saturday, pledging to increase defense spending by 20 percent and urging China to cooperate in establishing a military buffer zone to lower tension in the Taiwan Strait.

The 162-page document, issued after long delays and extensive debate among President Chen Shui-bian’s advisers, was designed as a guideline for this and future governments in defending the self-ruled island against any attack from China, officials said. Reflecting Chen’s dream of full Taiwanese independence, it said that Taiwan’s “overall strategic goal is to guarantee the country’s sovereignty.”

China had no immediate reaction. It has long insisted that Taiwan is a province that must return to the Chinese fold. It has vowed to use force, as a last resort, to prevent the island and its 23 million inhabitants from attaining formal independence.

In a recent interview, Chen said Taiwanese intelligence had information that China has a plan to attack the island within 10 years, but this was not repeated in the strategy declaration.