Nader:

"Why don't we say what's on the minds of many legal experts; that the Obama administration is committing war crimes and if Bush should have been impeached, Obama should be impeached," Nader said in an interview with the anti-war Democracy Now! organization.

Nader's comments came before the U.S. on Saturday launched military strikes into Libya, but they are among the toughest criticisms Obama has endured from the left.

The consumer advocate participated in an anti-war demonstration outside the White House this weekend, during which more than 100 protesters were arrested.

The U.S. sought the passage of a U.N. Security Council resolution and commitments from European and Arab nations before taking action in Libya to thwart the country's leader, Col. Moammar Gadhafi, from killing civilians amidst a rebellion against his regime.

Nader's comments, however, were mainly directed at Obama's prosecution of the Afghanistan war. Some liberal activists have objected to Obama's decision to escalate the war and are unhappy with government's treatment of Bradley Manning, the Army private accused of leaking classified documents to the organization WikiLeaks.