The alleged chemical weapon attacks against anti-government rebels near the Syrian capital of Damascus is simply "unacceptable," according to McKeon.
Administration officials said over the weekend they have “little doubt” that Assad's forces used poison gas. According to opposition groups, the death toll from the attack stands at more than 1,000.
Use of those weapons crosses "red line" set by the Obama administration, which would trigger a U.S. military response.
U.S. warships, armed with long-range cruise missiles, are already on station off the coast of Syria ready to conduct surgical strikes against government positions in the country.
That said, Sen. Bob CaseyBob CaseyA guide to the committees: Senate GOP loses top Senate contenders How many GOP senators will stand up to megadonor DeVos? Just 2. MORE (D-Pa.) warned against the difficulties Washington and its allies face if U.S. military action begins in Syria.
However, allowing Assad's forces to amass and use chemical weapons in the country could further destabilize the region.
"Addressing the crisis in Syria at this stage will be extremely difficult, but every day that Assad remains in power helps Iran and Hezbollah and threatens stability across the region," Casey said in a statement Monday.
President Obama reportedly discussed Washington's military options in Syria with British Prime Minister David Cameron and French President François Hollande after an emergency meeting of Obama's national security team on Saturday at the White House.
On Monday, Secretary of State John KerryJohn KerryWhere do we stand on the Iran deal under President Trump? New York Knicks owner gave 0K to pro-Trump group A bold, common sense UN move for the Trump administration MORE vowed there would be “consequences” for what he deemed an “undeniable” chemical weapon attack by Assad's forces.
“Make no mistake: President Obama believes there must be accountability for those who would use the world's most heinous weapons against the world's most vulnerable people," Kerry said.
However, McKeon and other congressional Republicans are demanding the White House seek lawmakers' approval before launching any military strike against Syria.
“I don’t think there’s any question in our administration’s mind that chemical warfare has been used," Sen. Bob CorkerBob CorkerA guide to the committees: Senate Republicans play clean up on Trump's foreign policy GOP Congress unnerved by Trump bumps MORE, the top Republican on the Senate Foreign Relations panel, said Monday.
"I hope they come to Congress for an authorization at some point," he said during an interview on MSNBC.
McKeon echoed Corker's statement calling upon Obama to seek congressional authorization for military operations.
"The President established a red line policy," McKeon said. "I expect the Commander in Chief would consult with Congress in the days ahead as he considers the options available to him."