Malaysia today warned foreign forces to stay out of the Straits of Malacca and called for a comprehensive plan to protect the busy waterway from terrorism and crime.

Deputy Prime Minister Najib Abdul Razak, who is also defence minister, said there was a need for stepped up security in the strait and that littoral states Malaysia, Indonesia and Singapore must have the ultimate say.

"It is a sad fact that many of those who use the straits take it for granted," he said when opening a three-day conference on improving security in the narrow waterway.

"Any assumption that its users have absolute freedom to utilise it, including for military purposes, reflects a lack of respect for the rights of the littoral states and a misunderstanding of international law."

The 960-kilometre strait, through which about half the world's oil supplies and a third of global trade passes, runs along the coasts of Indonesia, Malaysia and Singapore.

Najib did not name any countries but both Malaysia and Indonesia have opposed the idea of US marine patrols, fearing it may provoke Islamic militants and impinge on their sovereignty. Tiny Singapore however, supports a US role.

Najib said traditional security threats such as piracy were the most pressing issue, as well as growing use of the strait as a conduit for movement of illicit goods and illegal human cargo, navigational safety and environmental issues.

"The crux of the matter lies with ensuring comprehensive security for the straits. No doubt it may prove to be a delicate matter as it involves sacred national values such as sovereignty and autonomy but to achieve this ambitious task, the foundation must be laid now," he said.

Stalking horse

At a news conference later, Najib said Malaysia was still studying the ramifications of the US-proposed Regional Maritime Security Initiativeto protect the waterway but said "interdiction" operations must fall squarely on littoral states.

Thomas Doughton, political affairs counselor at the US embassy in Kuala Lumpur, told the conference the RMSI was not a unilateral US initiative and would not challenge the sovereignty of any state.

"RMSI is not a stalking horse for US navy patrols" but a capacity-building effort focusing primarily on law enforcement agencies rather than naval forces to improve crisis management and crisis prevention, he said.