The White House is keeping up its push for military action in Syria today in separate conference calls to the Senate's democratic and republican caucuses. The unclassified calls come a day before the House of Representatives will receive a classified, in-person briefing on Capitol Hill tomorrow.

Many lawmakers voiced opposition this week to what they perceive as inadequate collaboration with congress over the possibility of American intervention in that country's civil war. House Speaker John Boehner has expressed concern many members, currently out of town on recess, may not be able to make the meeting.

A senior administration official says today's calls with Senate "continue the Administration's consultations regarding the Assad regime's use of chemical weapons in Syria on August 21."

READ MORE: Everything You Need to Know About the Syrian Civil War

National Security Advisor Susan Rice, Secretary of State John Kerry, Defense Secretary Chuck, Hagel, Director of National Intelligence James Clapper and the vice chairman of the Joint Chiefs, Admiral James Winnefeld participated in the calls, according to the White House. Those officials also briefed ranking members of the House of Representatives in a similar call on Thursday.

Vice President Joseph Biden was also seen entering the White House today, although his public schedule indicated he would spend the weekend in his home state of Delaware.

Later today, Obama is set to deliver a statement on Syria from the Rose Garden at 1:15 p.m. ET.

RELATED: United Nations Weapons Inspectors Leave Syria as US Prepares for Possible Attack

There has been deep criticism in congress over the prospect of an American strike in Syria, from members of both parties. On Friday Senator John McCain, R-Ariz., disparaged what he predicts would be an attack that does not go far enough.

"The president apparently wants to have a kind of cosmetic strike, launch a few missiles and then say, 'Well, we responded,'" he said on NBC's Tonight Show. "This is the same president that, two years ago, said Bashar Assad had to go. It's also the president that said that there would be a red line if they used chemical weapons. Maybe that red line was written in disappearing ink."

Senator Carl Levin, D-Mich., is one of a number of members fearful of a unilateral or U.S.-led strike.

"The United States should not undertake a kinetic strike before the U.N. inspectors complete their work," he said in a written statement Friday. "And that the impact of such a strike would be weakened if it does not have the participation and support of a large number of nations, including Arab nations."

Still left are lawmakers including Sen. Rand Paul, R-Ky., who protest on libertarian grounds of non-intervention. Over a hundred members have written to President Obama imploring him to seek congressional approval.

Related: How Obama Can Bypass Congress on a Syria Strike

The debate has also opened up new discussion of the 1973 War Powers Act, which gives the Commander in Chief the authority to conduct military activity for 60 days without a formal declaration of war from Capitol Hill.

Additionally Congress has not formally declared war since World War II: The Korean War, Vietnam, Gulf War, Iraq, Afghanistan, and most recently Libya were all conducted without an official declaration.