Uruguay says it hopes to give landlocked Bolivia an outlet to the sea.
President José Mujica and his Bolivian counterpart Evo Morales signed an agreement Thursday to let Bolivia use a planned deep-water port on the Atlantic. Morales said they are still working out details on how it will be used. To get goods to the port by land, Bolivian shippers would have to cross part of Argentina, Paraguay or Brazil.
Mujica has been promoting the port project near the border with Brazil, but so far construction has not begun.
Bolivia has long tried to recover part of a coastline it lost to Chile in the late 19th century. Chile has given Bolivia special rights to a port in the area, but has refused to grant it territory.