West Sepik capital Vanimo is close to Indonesia's Papua Province and its capital Jayapura, with the border closed three months ago in order to stop the spread of coronavirus.
Wouwou said West Sepik acted early, with awareness campaigns and the deployment of a rapid response team, to implement public restrictions, Radio New Zealand International reported.
But he said there was still not enough security forces to stop people, particularly PNG vanilla traders, crossing the border through the bush, as well as by sea.
"Normally they go through at night time to do their vanilla trading.
"Though we have personnel staying in Vanimo - defence force and police force - but still we don't have enough man forces to ensure we secure our borders."
Meanwhile, dozens of Papua New Guinea citizens stranded in neighbouring Indonesia were waiting approval from the state of emergency controller, David Manning, to be repatriated.
Up to 120 citizens, mainly people recently released from prison, had been stuck for weeks in Jayapura pending permission to be transferred by authorities across to West Sepik Province, Radio New Zealand International reported.
"So that is what we are looking for now, waiting for him to give his approval. Once we have approval in order, then we might as well ask the Indonesian government to bring them across to the border and we'll pick them up from there," Wouwou said.