MANILA - Myanmar leader Aung San Suu Kyi has come under growing pressure to address the plight of her nation's displaced Rohingya Muslim minority in meetings here on the sidelines of Asean's summit of world leaders.

United Nations Secretary-General Antonio Guterres on Tuesday (Nov 14) told the Nobel laureate "to ensure humanitarian access, safe, dignified, voluntary and sustained returns, as well as true reconciliation between communities".

Ms Suu Kyi also met US Secretary of State Rex Tillerson who also discussed with her the situation in Rakhine.

A senior State Department official told journalists that Mr Tillerson, who will visit Myanmar today (Nov 15), will call on Myanmar's military to work with the civilian government to stop the violence and reach a "long-term peaceful solution".

He will "express concerns over… the violence and insecurity affecting the Rohingya and other local populations and discuss ways to help (Myanmar) end the crisis and chart a productive way forward", the official said.

On Ms Suu Kyi's resolve to solve the crisis, the official said, "I can assure you that she does… It's a unique power-sharing government in Myanmar, but she certainly wields a lot of authority and influence, and there's a lot she can do".

The United States has avoided outright criticism of Ms Suu Kyi. Supporters say she must navigate a path between outrage abroad and popular feeling in a majority Buddhist country.

More than 600,000 Rohingya have flooded into Bangladesh since late August, and now live in the squalor of one of the world's biggest refugee camps.

The crisis erupted after Rohingya rebels attacked police posts in Myanmar's Rakhine state, triggering a military crackdown that saw hundreds of villages reduced to ashes and sparked a massive exodus.

The Myanmar government insists military action in Rakhine is a proportionate response to violence by militants.

Following its first official investigation into the crisis, the army published a report this week in which it cleared itself of any abuses. However, it heavily restricts access to the region by independent journalists and aid groups.

The State Department official said Mr Tillerson will press the army to grant access to journalists and aid groups for a "credible investigation of abuses, and hopefully to hold those responsible for the abuses accountable".

A draft of a statement issued after this week's Asean meetings did not mention the Rakhine crisis besides assurances from individual states to offer humanitarian assistance to those displaced.

It instead focused on traditional concerns of the bloc.

Asean took a big step towards resolving contentious issues over the South China Sea and working together to deal with new threats from Islamist extremists.

Asean and China on Monday (Nov 13) agreed to begin talks on a "code of conduct" meant to prevent disputes over contested waters from escalating into violent confrontations.

In a news conference to mark the end of the Asean summit, Philippine President Rodrigo Duterte said: "Half the time during the interventions was taken by the issue of terrorism."

The Asean meetings were held just weeks after Philippine troops recovered the southern city of Marawi from Muslim militants that held parts of it for five months.

Experts have warned setbacks dealt on Islamic State in Iraq and Syria (ISIS) militants are giving rise to new threats, either from lone-wolf attacks or insurgencies.