WASHINGTON - A long-planned visit by US Vice-President Joe Biden to Japan, China and South Korea starting on Monday would take on a whole new dimension after a week of escalating tensions in the East China Sea.
While Mr Biden's agenda will still include its original elements - re-emphasising the rebalance towards Asia and discussing the Trans-Pacific Partnership free trade agreement - the trip will now likely be dominated by the task of calming the storm brewing over China's shift towards a more aggressive foreign policy stance.
Observers say he will have the difficult task of asserting America's position without coming off as lecturing China. The White House has stressed that it wants to advance the US-China relationship.
In its latest provocative move, Beijing declared a new air defence zone last week that overlaps with those of its neighbours and covers the islands it is disputing with Japan. Beijing now wants aircraft to submit flight plans when traversing the area.
The air defence identification zone (ADIZ) falls outside Chinese territorial waters but Beijing argues that there is a sound legal basis for its establishment.
The United States, Japan and South Korea all have similar zones, but unlike the Chinese, do not require planes to register flight plans unless they intend to fly into national airspace.
The move sparked condemnation from the US, Japan and South Korea and raised concerns from countries throughout the Asia-Pacific - Singapore included - of a potential flash point.
In defiance of the Chinese regulations, American, Japanese and South Korean military jets flew through the zone over the past week.
While US commercial airlines United, American and Delta - following US government advice - notified the Chinese authorities of their flight plans, Japan has stopped its airlines from doing so.