TEHRAN China Tuesday denounced U.S. plans to sell Taiwan a sophisticated package of weapons which would significantly boost the island's naval defense against a possible Chinese attack.

While the United States rebuffed Taiwanese requests for Arleigh Burke Class destroyers mounted with state-of-the-art Aegis radar, it still approved substantial sales including eight diesel-powered submarines.

Taiwan has yet to react to the decision, to be formally announced by the White House later Tuesday, but analysts said the package would be the most significant arms sale to the island in a decade.

U.S. officials said Taiwan would also be offered four Kidd-Class destroyers, 12 P-3C submarine-hunting patrol aircraft, self-propelled artillery and a briefing on PAC-3 missiles that Taiwan may request in the future.

China, which considers Taiwan part of its territory, expressed "extreme concern" over the proposed sale, saying it would violate Sino-U.S. agreements and escalate tension across the Taiwan strait.

"China has always been seriously opposed to weapons sales to Taiwan and strongly opposed to such sophisticated weapons," Foreign Ministry spokeswoman Zhang Qiyue told a biweekly briefing, cited by AFP.

"If the U.S. side disregards Chinese opposition to the sale of the above weapons to Taiwan, it will constitute a serious violation of China's sovereignty and gross interference in China's internal affairs," said Zhang.

Meanwhile, Taiwan politicians and analysts welcomed U.S. decision to provide the biggest arms package for the island in a decade, but dismissed fears the offer of submarines would further strain ties with China.

"We are very pleased. Submarines are our first priority," Steve Chou, an opposition legislator and retired lieutenant-general, told Reuters.

The U.S. offer would be the biggest arms package for Taiwan since the early 1990s when the island bought 150 F-16 fighters from the United States and 60 Mirage 2000-5 fighters and six Lafayette-class frigates from France worth billions of dollars.

Taiwan Defence Ministry spokesman Huang Suey-Sheng said: "We must obtain modern weapons for the sake of security in the Taiwan strait and peace in the Asia-Pacific." But he declined to comment on the reported sale.