HOURS after slamming China for its reclamation activity in the South China Sea, which he said altered the regional status quo, United States Defence Secretary Ashton Carter yesterday boarded a US Marine Corps aircraft to tour the crowded Malacca Strait.
Accompanied by The Straits Times as well as the travelling press from Washington in an Osprey plane, Mr Carter and top US Defence Department officials toured the waterway for an hour after taking off from Paya Lebar Air Base.
The tilt-rotor Osprey, which lifts off like a helicopter but cruises as a turboprop plane, sometimes flew as low as 500 feet over parts of the strait.
Pentagon officials said Mr Carter wanted a "first-hand grab" of the dense maritime traffic in the strait, which they described as one of the world's two most important choke points - the other being the Strait of Hormuz.
They pointed out that 50 million barrels of oil go through the Malacca Strait daily, including fully 80 per cent of the oil imported by China and Japan.
At its narrowest, the strait is only 2.7km wide.
These factors underscored the link between security and prosperity in the Pacific. But the actions by some countries in the region, notably China, have begun to challenge the old rules that had provided stability.
"I imagine some of what he saw today will figure in his speech tomorrow," said a senior military official with Mr Carter.
"Freedom of navigation is going to be a major theme. It is important for China to realise they have skin (stakes) in the game."
Mr Carter did not speak to the media after his aerial tour.
But he told the US media at the start of his Asia trip on Thursday that the US was trying to maintain a regional security structure that has helped the region prosper for the past 70 years.
He stressed that the US would continue to fly over the South China Sea as it had done for years, and demanded a halt to the reclamation activity being pursued by China in the contested waters, which, some analysts believe, could be a prelude to announcing an air defence identification zone.
"We will continue to do that: Fly, navigate, operate. So, that's not a new fact," he said.
Mr Carter also called on Prime Minister Lee Hsien Loong and Defence Minister Ng Eng Hen earlier yesterday.