Washington (CNN) -- The top diplomats of the United States and the European Union are discussing "additional steps" to pressure Syria into halting its widely deplored crackdown on peaceful protests.
Secretary of State Hillary Clinton and Catherine Ashton, foreign policy chief of the European Union, spoke to reporters Tuesday in Washington about the clampdown.
"I think we're all very aware that the situation is so grave that it's now in a situation where we need to consider all of the options," Ashton said.
The United Nations said on Friday as many as 850 people have been killed over the past two months during demonstrations, and thousands have been arrested. Syrian citizens have a range of political grievances toward the government.
"The number of people that we know have died (and) the number of people that we believe are in detention is extremely alarming, and what's happening while I'm here is the 27 ambassadors in Brussels are meeting to discuss on a daily basis what more we could and should do," Ashton said, referring to the EU's Belgian headquarters.
Clinton, noting that the United States and the European Union have imposed sanctions against senior Syrian officials, said that on Tuesday the diplomats "discussed additional steps that we can take to increase pressure and further isolate" the Bashar al-Assad regime.
A U.S. official told CNN Tuesday that more sanctions will be announced "in the next 48 hours."
Officials with the U.S. Treasury Department declined to comment.
"Our message has been clear and consistent from the beginning," Clinton said: "Stop the violence and the arrests, release all political prisoners and detainees and begin to respond to the demands of the people by a process of credible and inclusive democratic change."
President Barack Obama is expected to use a major speech on the Middle East on Thursday to reaffirm basic U.S. principles and policies regarding the region while also toughening his administration's stance against Syria's crackdown on pro-democracy demonstrators.
He is expected to come out strong against al-Assad's violent response to protesters in his country, U.S. officials said. They expect additional U.S. sanctions on Syria to be announced before the speech and said the new measures could target al-Assad by name.
CNN's Elise Labott contributed to this report.