"Libya is the funnel of Africa," Wauquiez told radio station France Info. "Flows of illegal immigrants from countries such as Liberia, Somalia and Eritrea pass through Libya."
France is taking the side of Italy, which is asking the European Union for help in dealing with the arrival of thousands of refugees leaving north Africa. But several countries, including Austria, Germany and Sweden, have opposed the proposal.
"We must defend our frontiers on a European level," said Wauquiez. "What we're talking about isn't a few tens of thousands of illegal immigrants who could arrive in Europe; it's potentional 200,000 to 300,000 this year."
"Substantial assistance" was being discussed at a meeting of EU officials Wednesday, diplomats said.
The UN High Commissioner for Refugees earlier repeated calls for hundreds of planes to help save crowds at Libya's borders with Egypt and Tunisia.
The EU will hold an extraordinary summit on the question in Brussels on 11 March.
Wauquiez said an aid package for north Africa needs to be agreed by the EU, the United States and Asian countries.
"There is a complete determination across Europe to get rid of Moamer Kadhafi [the Libyan president] and make sure the situation doesn't turn into a blooodbath," Wauquiez added.