Biden spoke Monday during a visit to the port in Charleston, S.C., along with Transportation Secretary Anthony Foxx.
The two visited a port terminal in nearby Mount Pleasant and spoke with longshoremen before speaking to a crowd of about 300 on the docks.
Charleston is working on a harbor deepening project expected to cost more than $300 million. Biden says he didn't want to short circuit the study but said he knows what the results will be -- that the harbor should be deepened.
Later, Biden was heading to Savannah, Ga., to visit the port there. The ports of Charleston and Savannah are in keen competition.