ABOARD A US MILITARY AIRCRAFT (REUTERS) - US Defence Secretary Chuck Hagel strongly suggested the United States was positioning naval forces and assets in anticipation of any decision by President Barack Obama to order military action on Syria after apparent chemical weapons use.

"The Defence Department has responsibility to provide the president with options for all contingencies," Mr Hagel on Friday told reporters traveling with him to Malaysia.

"And that requires positioning our forces, positioning our assets to be able to carry out different options - whatever options the president might choose."