Four U.S. destroyers are “ready to go” in striking Syria as soon as President Obama gives the green light. Meanwhile, U.S. intelligence agencies is reported to have intercepted communications aimed at proving Syria’s Bashar Assad as the perpetrator behind Wednesday’s chemical weapons attack that killed hundreds of civilians, the Associated Press reports.

“There’s no doubt who is responsible for this heinous use of chemical weapons in Syria: the Syrian regime,” said U.S. Vice President Joe Biden.

Administration officials argued that Assad’s actions posed a direct threat to U.S. national security, providing President Barack Obama with a potential legal justification for launching a strike without authorization from the United Nations or Congress.

“Allowing the use of chemical weapons on a significant scale to take place without a response would present a significant challenge to, threat to the United States’ national security,” White House spokesperson Jay Carney said.

Assad has denied using chemical weapons and called the allegations “preposterous.”

Officials said the goal was not to drive the Syrian leader from power or impact the broader trajectory of Syria’s civil war with death tolls exceeding 100,000 after three years since it started.

"The options we are considering are not about regime change," Carney told reporters.

Defense Secretary Chuck Hagel said military forces stand ready to strike Syria immediately if the commander in chief gives the order. “We are ready to go,” Hagel said during a television interview while traveling in Asia, according to AP.