BRUSSELS • The European Union (EU) will start preparing sanctions against Myanmar generals over the killing of Rohingya Muslims by formally calling on the bloc's foreign policy chief next week to draw up a list of possible names.

It is also expected to target Cambodia for a crackdown against the opposition ahead of elections in July.

"Ministers will call on (Federica) Mogherini to propose restrictive measures on senior members of the Myanmar military for systematic human rights abuses without delay," one diplomat told Reuters on Thursday, referring to EU sanctions.

The Financial Times reported yesterday that possible measures against Cambodia include a rollback of trade preferences.

The EU will warn Cambodian Prime Minister Hun Sen of possible action should the situation not improve in the run-up to elections, the daily said. The ministers will order enhanced monitoring of the "everything but arms" agreement, under which Cambodia exports goods including garments and textiles duty-free to the EU. 

Germany said on Thursday it had suspended preferential treatment in issuing visas for private travel by Cambodian government members, including Mr Hun Sen and his family, as well as high-ranking military officials and the president of the Cambodian Supreme Court.

Any new travel bans and asset freezes would be the EU's toughest measures yet on Myanmar military to hold it accountable for the abuses against the Rohingya, likely joining United States and Canadian sanctions already in place.

On Monday, foreign ministers will also ask Ms Mogherini and the EU's foreign service, the European External Action Service, to look at ways to strengthen the bloc's 1990s-era arms embargo on Myanmar that remains in place.

In a statement expected to be released on Monday at a regular gathering of EU foreign ministers, the bloc is also expected to reiterate its call for the release of two Reuters reporters detained on Dec 12 over accusations that they had violated Myanmar's Official Secrets Act.

The two had been working on an investigation into the killing of 10 Rohingya Muslim men who were buried in a mass grave in Rakhine state after being hacked to death or shot by ethnic Rakhine Buddhist residents and soldiers.

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

About 655,000 Rohingya have fled Rakhine for Bangladesh, according to the United Nations.