More than 50 U.S. State Department officials have signed an internal memo that criticizes U.S. policy in Syria and calls for air strikes against Syrian government forces.
The memo was reportedly signed by 51 mid- and high-level State Department officers involved in formulating U.S. policy in Syria, The Wall Street Journal reports.
The "dissent channel cable" calls for "targeted military strikes" against Syrian forces loyal to President Bashar al-Assad amid the breakdown of a cease-fire agreed to earlier this year.
U.S. Secretary of State John Kerry said from Copenhagen on June 17 that the memo was an "important statement" but he had not seen it. He said he would discuss the issue when he returned to Washington.
Air strikes against Syrian forces or Assad government targets would be a major change in the Obama administration's policy of not directly intervening in the Syrian civil war.
More than 270,000 people have been killed and millions of others forced to flee their homes since the civil war began in 2011.
While the signing of dissent cables is not uncommon, the number of signatures on the document is considered unusually large.
"That is an astonishingly high number," said Robert Ford, who resigned in 2014 as U.S. ambassador to Syria over policy disagreements.
State Department spokesman John Kirby said in an e-mail that "we are reviewing the [dissent channel] cable now...and I am not going to comment on the contents."
Kirby said the "dissent channel" is an official forum that allows State Department employees to express alternative views.