European Union foreign ministers agreed on Monday to prepare sanctions against Myanmar generals over the killings of Rohingya Muslims and to strengthen the EU arms embargo, accusing state security forces of grave human rights abuses.

As reported by Reuters last week, foreign ministers meeting in Brussels asked the EU's foreign policy chief, Federica Mogherini, to draw up a list of names to be hit with EU travel bans and asset freezes.

In a statement, ministers called for "targeted restrictive measures against senior military officers of the Myanmar armed forces responsible for serious and systematic human rights violations without delay".

The measures would be the EU's toughest yet to try to hold the Myanmar military accountable for the abuses, likely joining US and Canadian sanctions already in place.

Foreign ministers also want to strengthen the bloc's 1990s-era arms embargo on the Southeast Asian country that remains in place, although they did not give details.

Reuters investigations have highlighted the killing of Rohingya Muslim men who were buried in a mass grave in Rakhine state after being hacked to death or shot by ethnic Rakhine Buddhist neighbours and soldiers.

No names of generals to be targeted for sanctions have been yet discussed, two diplomats said, but the United States said in December it was sanctioning Major General Maung Maung Soe, who is accused of a crackdown on the Rohingya minority in Rakhine.

One EU diplomat said the EU's list was likely to include more than just one senior military officer.

The EU's decision to consider sanctions reflects resistance to such measures in the UN Security Council, where veto-wielding powers Russia and China said this month they believe the situation in Rakhine was stable and under control.

The United States, as well as United Nations, have described the military crackdown in Myanmar as "ethnic cleansing". More than 680,000 people, mostly Rohingya, have fled Rakhine for shelter over the border in Bangladesh, the EU said.

Myanmar has denied most allegations of abuses and asked for more evidence of abuses, while denying independent journalists, human rights monitors and UN-appointed investigators access to the conflict zone.