WASHINGTON, March 21: Internal pressure increases on US President Barack Obama to define his country's role in Libya as allied forces continue to attack government targets in the Arab state.“Before any further military commitments are made, the administration must do a better job of communicating to the American people and to Congress about our mission in Libya and how it will be achieved,” said speaker of the US House of Representatives John Boehner.

On Sunday, a prominent Democratic lawmaker, Diana DeGette, called for an emergency congressional session to consider the US military action in Libya. Under the US War Powers Act, the president must inform Congress of any military resolution within 48 hours. It also limits military action to 60 days without further congressional approval.

The White House, however, said President Obama briefed Speaker Boehner and other congressional leaders on Friday before committing US military in Libya.

Separately, a number of liberal Democrats raised objections to the mission during a House Democratic Caucus conference call.

One of them, Congressman Dennis Kucinich, said that Mr Obama lacked the authority to clear the Libya operation and that “Congress should be called back into session immediately to decide whether or not to authorise America's participation in a military strike.”

The action in Libya also has split the top ranking Democrat and Republican on the US Senate Foreign Relations Committee. Chairman John Kerry, a Democrat, joined forces with Republican Senators John McCain and Lindsey Graham and Independent Joe Lieberman to call for quick, decisive action, while Senator Richard Lugar and a host of Democrats urged caution and demanded that the president seek a declaration of war from Congress. In the House, a vocal group of Republicans joined liberal Democrats in expressing concerns about the Libya operation.

Republican Congressmen Jason Chaffetz, Ron Paul and Justin Amash questioned the constitutionality of the operation and expressed concerns about yet another US military intervention in an Arab country.

“Unless there's a clear and present danger to the United States, I don't think you use US forces in North Africa in what is the equivalent of a civil war,” Mr Chaffetz said.

“With regard to Libya, we say what's the goal? What is our role?” Republican Senator John Barrasso asked. The current mission, he warned, could see US forces involved for “weeks and months.”