By Arshad Mohammed and David Brunnstrom
WASHINGTON (Reuters) - The United States on Wednesday labelled the Myanmar military operation against the Rohingya population "ethnic cleansing" and threatened targeted sanctions against those responsible for what it described as "horrendous atrocities."
"The situation in northern Rakhine state constitutes ethnic cleansing against the Rohingya," U.S. Secretary of State Rex Tillerson said in a statement, using a term he avoided when visiting Myanmar, also known as Burma, last week.
"The United States will also pursue accountability through U.S. law, including possible targeted sanctions" against those responsible for the alleged abuses, which have driven hundreds of thousands of Rohingya into neighbouring Bangladesh, Tillerson said.
The United States shifted its stance in part to raise pressure on Myanmar's military and civilian leaders, who have shared power for the past two years under an uneasy arrangement after decades of military rule, to address the crisis.
Human rights monitors have accused Myanmar’s military of atrocities, including mass rape, against the stateless Rohingya during so-called clearance operations following Rohingya militants' Aug. 25 attacks on 30 police posts and an army base.
More than 600,000 Rohingya Muslims have fled Rakhine state in Buddhist-majority Myanmar, mostly to neighbouring Bangladesh, since the crackdown, which followed the insurgent attacks.
"These abuses by some among the Burmese military, security forces, and local vigilantes have caused tremendous suffering and forced hundreds of thousands of men, women, and children to flee their homes in Burma to seek refuge in Bangladesh," Tillerson said.
While repeating the U.S. condemnation of the insurgent attacks, he added: "No provocation can justify the horrendous atrocities that have ensued."
Myanmar's 2-year-old government, led by Nobel Peace Prize laureate Aung San Suu Kyi, has faced heavy international criticism for its response to the crisis, though it has no control over the generals with whom it has to share power.
"It’s not a situation that is completely under her authority, but certainly we are counting on her to show leadership and also to work through the civilian government with the military to address the crisis," a senior U.S. official told reporters in a conference call.
The term "ethnic cleansing" is not defined in international or U.S. law and does not inherently carry specific consequences, a second senior U.S. official said on the call.
He said the United States was analysing whether the events in Myanmar constituted genocide or crimes against humanity, which would violate international law, but said it has made no determination on either and that this would take time to assess.
A top U.N. official in September described the military actions as a textbook case of "ethnic cleansing," but the United States until Wednesday had avoided the term.
The United States has sought to balance its wish to nurture the civilian government in Myanmar, where it has been competing for influence with China, with its desire to hold the military accountable for the abuses. U.S. officials also worry that the mistreatment of the Rohingya Muslim minority may fuel radicalism.
Pressure had mounted for a tougher U.S. response to the Rohingya crisis before President Donald Trump's first visit to Asia this month to attend a summit of Southeast Asian countries, including Myanmar, in Manila.
U.S. government sources told Reuters in October that officials were preparing a recommendation for Tillerson that would define the military-led campaign against the Rohingya as ethnic cleansing, which could spur new sanctions.
In early November, U.S. lawmakers proposed targeted sanctions and travel restrictions on military officials in Myanmar.
Democratic U.S. Senator Jeff Merkley, part of a congressional delegation that visited Rakhine this week, told reporters there on Tuesday, "This has all the hallmarks of ethnic cleansing."
(Reporting by Doina Chiacu and Arshad Mohammed; Editing by Chizu Nomiyama and Steve Orlofsky)