The EU's new naval mission to block the flow of arms to Libya by sea got under way last week and Borrell - in a statement issued in the name of all 27 countries - vowed to make it work.
"The European Union remains determined to see the UN arms embargo in Libya fully respected," he said. He said further efforts were needed to "ensure the full and effective implementation" of the embargo, particularly through Libya's land and air borders.
Libya has been mired in chaos since the ouster and killing of long-time dictator Muammar Qadhafi in 2011, with rival administrations in the east and west vying for power.