Malaysia described the violence against Myanmar's Muslim Rohingya minority as "ethnic cleansing" on Saturday, ahead of a planned solidarity march in Kuala Lumpur expected to be led by Prime Minister Najib Razak.
The strongly-worded statement came after Myanmar said on Friday that Malaysia should respect sovereign affairs and follow Association of Southeast Asian Nations' (ASEAN) policy of non-interference in other member countries' internal affairs.
"The fact that only one particular ethnicity is being driven out is by definition ethnic cleansing," Malaysia's foreign ministry said in a statement.
"This practice must stop, and must be stopped immediately in order to bring back security and stability to the Southeast Asian region."
Muslim-majority Malaysia has been increasingly critical of Myanmar's handling of violence in northern Rakhine state that has sent hundreds of people fleeing across the border to Bangladesh, amid allegations of abuses by security forces.
The violence is the most serious bloodshed in Rakhine since communal clashes in 2012 that killed hundreds.
Persecution and poverty led thousands of Rohingya to flee Myanmar following the violence between Buddhists and Muslims there four years ago. Many of them were smuggled or trafficked to Thailand, Malaysia and beyond.
The Rohingya issue posed a threat to Malaysia's own security, Malaysia's foreign ministry said, adding that the high number of Rohingya in Malaysia and other neighboring countries made this an "international matter".
Myanmar's deputy director general of the President's Office U Zaw Htay told the Myanmar Times on Friday that Malaysia should respect sovereign affairs.
Malaysia summoned Myanmar's ambassador last week over the crackdown on Rohingya. It also cancelled the national soccer team's friendly under-22 matches with Myanmar in protest.
Senior government leaders, led by Najib, are expected to participate in the solidarity march on Sunday.