China and Russia blocked a proposed UN Security Council statement on Friday that would have expressed concern over the tense situation in Myanmar's Rakhine state, diplomats said.
Myanmar's military carried out a four-month offensive against the Rohingya in northern Rakhine that UN human rights investigators have said likely resulted in atrocities and crimes against humanity.
British Ambassador Matthew Rycroft told reporters "there was no consensus in the room" for the statement.
Diplomats said China and Russia had raised objections, but the diplomatic missions of the two countries did not respond to requests from AFP for information.
The proposed British-drafted statement "noted with concern renewed fighting in some parts of the country and stressed the importance of humanitarian access to all the areas."
"We support the peace process and are one of the largest bilateral humanitarian aid donors, including in Rakhine state," said Rycroft, whose country holds the presidency of the Security Council this month.
An agreed statement expressing concern could have led to further action, but the move by China and Russia -- which both have veto power -- was seen as a clear signal that Myanmar should be left off the council agenda.
UN rights officials have accused the Myanmar military of extrajudicial killings, gang rapes and probable ethnic cleansing during the campaign against the Rohingya.
The 1.1 million Rohingya are loathed by many from the Buddhist majority, who insist they are illegal immigrants from Bangladesh even though many have lived in the country for generations.