More than 4,000 Sailors and Marines have been ordered to redeploy to quake-torn Haiti, U.S. Navy said on Wednesday.

The troops redeployed under the order from Admiral Michael Mullen, the chairman of the Joint Chiefs of Staff, are from the Nassau Amphibious Ready Group and the 24th Marine Expeditionary Unit, according to a statement from the U.S. Second Fleet.

The amphibious group left Norfolk, Virginia on Monday on a regularly scheduled deployment and received an order a day later to divert to Haiti, the statement said.

The total number of U.S. troops due to be in Haiti in the next few days will be above 15,000 under the new deployment.

"The ARG/MEU will provide an array of helicopter and amphibious landing craft assets, significantly increasing the ability to quickly provide relief supplies where they are most needed," the statement said.

"In addition, the Marines assigned to 24 MEU will be able to provide an additional force capable of providing a secure environment for the ongoing relief efforts ashore in Haiti."

A strong earthquake hit Haiti on Jan. 12, 75,000 were killed while 250,000 injured and a million left homeless, according to the Haitian government's latest estimates.