On Friday, NATO’s Supreme Allied Commander Gen. Philip Breedlove posted photos to his personal blog of what he claimed were Russian forces operating inside Ukraine in uniforms without insignia. As the Daily Beast first reported last month, the U.S. intelligence community since late February has seen Russian special operations officers infiltrating throughout eastern Ukraine.

Behind the scenes, there’s shock and alarm inside the Obama administration about the recent actions by Russian forces. A senior administration official told The Daily Beast Sunday that the thinking inside the administration had been to wait until this Thursday before moving forward with any new sanctions. That’s the day U.S., EU, Russian, and Ukrainian governments are scheduled to meet in Geneva.

But given the new violence, the Obama administration has now moved to ready sanctions as early as Tuesday, the official said, cautioning that no final decision has been made. State Department, White House, and Treasury Department officials have been reaching out to their European counterparts over the weekend to persuade them to join a new sanctions regime. The E.U. Foreign Ministers will meet in Brussels Monday.