The 15-member Security Council met behind closed doors on Wednesday, at the request of Sweden and Britiain, to discuss the crisis for the second time since it began and agreed to publicly condemn the situation.
Speaking ahead of the meeting, Antonio Guterres called the situation for the Rohingya refugees "catastrophic" and "completely unacceptable", acknowledging that the minority group was being ethnically cleansed in the Buddhist-majority nation, Al Jazeera reported.
Around 370,000 of Myanmar 's minority Rohingya population have fled the country's western state of Rakhine into neighbouring Bangladesh in recent weeks, according to the UN.
The violence began on August 25, after Rohingya fighters attacked police posts, prompting a military crackdown.
"I call on the Myanmar authorities to suspend military action, end the violence, uphold the rule of law and recognise the right of return of all those who have had to leave the country," the UN chief said at the press conference in New York.
Guterres' comments mirrored those of UN human rights chief Zeid Ra'ad al-Hussein, who denounced the situation in Myanmar as "a textbook example of ethnic cleansing" on Monday.