The Obama administration was inching closer to a decision on how and whether to strike Syria, after Secretary of State John Kerry and the White House both declared that the evidence showing chemical weapons were used in a deadly attack last week is "undeniable."

"What is before us today is real, and it is compelling," Kerry said.

Administration officials, signaling they might not wait until U.N. inspectors finalize their own investigation, now say that the international community must respond to the use of chemical weapons. The comments from top U.S. officials on Monday signaled a shift in tone, with military action looking more likely than it did just a day or two ago.

Two administration officials said the U.S. was expected to make public a more formal determination of chemical weapons use on Tuesday, with an announcement of Obama's response likely to follow quickly. [Link]