U.S. Secretary of State Hillary Clinton and Liberian President Ellen Johnson Sirleaf signed a statement of intent at the State Department establishing the dialogue.
"Today, we're taking another important step to deepen the partnership between our nations and to support Liberia as it continues down the path of democratic and economic reform," Clinton said on the occasion.
"The partnership dialogue we are about to sign will expand the cooperation between our countries and ensure high-level engagement for years to come," she added.
Under the agreement, the two countries will engage in three key areas -- agriculture and food security, energy and power infrastructure, and human development with focus on expanded access to education and employment for the Liberians.
Since the civil war ended in Liberia in 2003, the U.S. and the West African country have taken "significant" steps to strengthen democracy and promote a business environment conducive to trade and investment, the State Department said.
Sirleaf, who shared the 2011 Nobel Peace Prize, pledged continued efforts to build "a post-conflict success story."