Admiral James Loy said the renewed search operation is "quite simply an effort by the US coastguard to respond to the British government request."
He said he is not aware of any new information that would lead to the search renewal.
"When our best international ally is asking for continued service from Coast Guard here in the United States, we are going to respond to that request," Admiral Loy said.
With no sign of a life raft or of debris, and with nearly 20,000 square miles having been searched, the hunt continues for another day.
Veteran yachtsman Tony Bullimore tells ITV News that there is a "strong possibility" the yachtsmen are still alive in the life raft.