WASHINGTON - Speaking to an audience of academics, policy-makers, diplomats and government officials at the Centre for Strategic and International Studies in Washington on Wednesday, Malaysian Prime Minister Najib Razak focused on shared security concerns and cooperation with the US.

He voiced commitment to isolate North Korea, saying, "Asia must not be held hostage to the prospect of either a WMD (weapons of mass destruction) or conventional war breaking out in our midst. The stakes are simply too high."

And he expressed grave concern over the crisis in Myanmar's Rakhine state which has seen more than 300,000 Rohingya Muslims fleeing to Bangladesh.

"I believe the world is almost completely united in being appalled by the latest wave of violence - which also has the potential to radicalise desperate young people enraged by their government's treatment of them" Datuk Seri Najib warned.

Citing a slew of US-Malaysia joint drills, he said: "Many of these operations have evolved in complexity over the years. This marks a growth in trust and capability between our forces. Military operations have increasingly involved crossing between the physical and virtual domains, and I strongly encourage our forces to share their expertise and experiences as military doctrines, rules, and norms develop in cyber space."

On the threat of the Islamic State, he said: "Daesh has ensnared some of our citizens both in life and in death, from Mosul to Marawi." Daesh is an Arabic acronym for the Islamic State in Iraq and Syria, or ISIS.

"Men, women, and children from Malaysia have travelled to Syria and Iraq to fight for a false cause, burning their passports, and hoping never to return. Others seek to kill members of our Government and other prominent figures."

"These people... are our enemies just as much as they are your enemies. Indeed, by claiming their terrorism is Islamic in nature, these individuals blaspheme against our religion - something for which we simply cannot forgive them. I want to reiterate here, in your capital, that Malaysia is United States' firm ally in this battle."

He emphasised, however, the importance of fighting the ideology that drives terrorism through narratives that counter online and offline extremist propaganda.

"We look forward to even closer intelligence and law enforcement cooperation with United States, and in sharing our expertise in countering radicalism and violent extremism of all ideologies," Mr Najib said.

Moving to North Korea, an issue of critical importance to the US which this week secured a new round of UN Security Council sanctions against Pyongyang, Mr Najib said: "Let me be very clear - there can be no place for the use or proliferation of WMDs. They pose a grave concern to the peace, security, and stability of the region and the world."

"Malaysia has been consistent in pressing North Korea to fully comply with all its obligations under the relevant UN Security Council resolutions, and to return to the negotiating table, with a view to achieving the denuclearisation of the Korean Peninsula," he said, adding that he had discussed the issue at length with President Donald Trump during their meeting on Tuesday at the White House.

On the Rakhine state crisis, the Malaysian premier said US President Donald Trump shared his concern.

In a separate joint statement issued on Wednesday, the two leaders called for "an end to the violence targeting civilian populations, and discussed the need for a strong international community response for the hundreds of thousands of individuals who have been victimised and displaced by violence, including those who have arrived in Bangladesh."

"Both sides urged the Myanmar government to end the violence against innocents and ensure that humanitarian relief reaches victims immediately."

The joint statement also mentioned the South China Sea, where China and several other countries in the region have overlapping claims. They called on all disputing parties to, "exercise self-restraint in the conduct of activities and refrain from action that erodes trust and confidence, and escalates tension, including the militarization of outposts."

"All maritime claims must be based on and resolved in accordance with international law as reflected in the 1982 United Nations Convention on the Law of the Sea," the statement said.

Mr Najib 's visit to the White House was the first by a Malaysian prime minister since 2004.

"He's made a good impact" a diplomat who attended the CSIS talk told The Straits Times.

"He is very articulate and does not shy away from anything" the diplomat said.

This included the sensitive issue of an ongoing Department of Justice investigation into kleptocracy at Malaysia's 1MDB.

In a speech on Tuesday night at the US-Asean Business Council, Mr Najib told industry leaders he had addressed the 1MDB issue and maintained that it was being used by the political opposition to try and bring his government down.