The director of the US Central Intelligence Agency has warned that China's military modernisation is tilting the balance of power in the Taiwan Strait and increasing the threat to US forces in the region.

Delivering the agency's annual assessment of worldwide threats on Wednesday, Porter Goss, a former Republican congressman who was named in September to head the CIA, dropped any mention of the co-operative elements of the US-China relationship that characterised recent CIA statements. Instead, he said China was making determined military and diplomatic efforts to “counter what it sees as US efforts to contain or encircle China”.