The military says its "clearance operations" in northern Rakhine state are aimed at flushing out Rohingya militants who attacked police posts on August 25.
But the violence has engulfed the border region and triggered an exodus of more than 400,000 Rohingya to Bangladesh, where they have told of soldiers slaughtering civilians and burning down entire villages.
UN leaders have described the campaign as having all the hallmarks of "ethnic cleansing" of the Rohingya, a stateless group that has endured years of persecution and repression.
Many in the Buddhist majority view the group as foreign interlopers from Bangladesh and deny the existence of a Rohingya ethnicity, insisting they be called "Bengalis".
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General Min Aung Hlaing, Myanmar's globe-trotting army chief, trumpeted that view in comments posted on his official Facebook page Saturday.
"They have demanded recognition as Rohingya, which has never been an ethnic group in Myanmar. (The) Bengali issue is a national cause and we need to be united in establishing the truth," the post said.
The defence of his army's operations comes amid strident global condemnation of the violence, which has strapped Bangladesh with the overwhelming task of providing shelter and food to a rising tide of desperate refugees.
On Sunday Myanmar's government hinted that it may not take back Rohingya who fled across the border, accusing those refugees of having links to the militants.
"Those who fled the villages made their way to the other country for fear of being arrested as they got involved in the violent attacks. Legal protection will be given to the villages whose residents did not flee," the government's Information Committee statement said.
Previous statements have said the country will set up relief shelters in northern Rakhine for Muslims "who can guarantee they are in no way connected to the terrorists".