By Caroline Gluck
BBC News, Taipei
The top US official in Taiwan has made a renewed plea for the island's legislature to pass an arms budget.
Similar previous comments by Mr Young infuriated Taiwanese MPs
Stephen Young, head of the American Institute in Taiwan, warned Taiwanese security is increasingly threatened by China's growing military might.
He said the island urgently needed to strengthen its missile defences in the face of China's continued military build-up.
China is thought to have more than 1,000 missiles targeting Taiwan.
Beijing has vowed to use force if necessary to prevent the island it regards as part of its territory from declaring independence.
This is not the first time that the de facto US ambassador to Taiwan has voiced his frustration at Taiwan's failure to pass an arms package that would allow it to buy US weapons to defend itself against any attack from China.
The initial arms package, worth around $18bn (£9bn), was first offered to Taiwan in 2001 and included anti-submarine aircraft, conventional submarines and PAK3 anti-missile batteries.
The budget has since been considerably slimmed down.
Mr Young said that since taking up his post 14 months ago he had heard a series of domestic excuses why Taiwan's legislature had been unable to pass the defence bill, although politicians from all sides had told him they supported the measure.
He said he was puzzled and frustrated by the inaction, urging legislators to set aside their partisan differences and pass the budget.
Similar comments he made last October though infuriated many opposition legislators who accused Mr Young of meddling in Taiwan's domestic affairs, with some even calling for his expulsion.
But Mr Young, who called himself a friend of Taiwan, was unapologetic, saying the US as Taiwan's security partner needed to speak out when it felt there was a need.