Malaysian Defence Minister Datuk Seri Hishammuddin Hussein is slated to join United States Defence Secretary Ashton Carter for a cruise on the USS Theodore Roosevelt in the South China Sea on Thursday.

Carter said this at a press conference after meeting Prime Minister Datuk Seri Najib Razak on the sidelines of the 3rd ASEAN Defence Ministers' Meeting (ADMM)-Plus in Subang near here Wednesday.

He noted that the presence of its naval vessels in the South China Sea was nothing new and it would continue to operate wherever international law permitted.

He said it should not be a major issue as what should be more of a concern was the scale of activity involving reclamation and militarisation which had taken place in the strategic waterway.

"I think the new development this year is the scale of reclamation and militarisation. US operations are not new either in the South China Sea or around the world," he said.

US and Chinese officials have sparred over the recent passage of the USS Lassen guided missile destroyer near at least one of the land formations China claims in the disputed Spratly Islands.

Touching on the ADMM-Plus, Carter praised ASEAN member states for their active discussions on the South China Sea issue.

The ADMM-Plus groups the 10 countries of Southeast Asia and eight other countries – Australia, China, India, Japan, South Korea, New Zealand, Russia and the US.

Malaysia is hosting the meeting this year as the holder of the rotating ASEAN chair. ASEAN groups Brunei, Cambodia, Laos, Myanmar, Malaysia, Indonesia, the Philippines, Singapore, Thailand and Vietnam.