The two rival Palestinian factions have failed to heal their political disputes since Hamas fighters expelled Fatah from Gaza in a short war in 2007
The province, a traditional stronghold of the Taliban and a major center for the opium production, has seen fierce fighting in recent weeks.
Taliban forces have made gains across Helmand in the past year, forcing government forces to abandon some bases and checkpoints in a bid to consolidate their defenses in and around key districts.
The statement gave no further details. But, around 100 American troops have been deployed in Helmand to provide support for the hard-pressed government troops, according to the US military.