Taiwan's Constitutional Court has ruled in favour of same-sex marriage, making the island the first place in Asia to recognise gay unions.

Taiwan's leader has urged China to engage in "calm and rational" dialogue to maintain peace, vowing not to give in to Beijing's recent moves to "threaten and intimidate" the self-ruled island.

China has said military officials are in contact with their American counterparts on "appropriately handling" the Chinese navy's seizure of a US Navy unmanned underwater glider, one of the most serious incidents between the forces in years.