Renaud Muselier, France's secretary of state for foreign affairs, urged Brazil and other nations to "reject a possible war that could endanger world peace."
Muselier delivered a letter from French President Jacques Chirac to Brazil's President Luiz Inacio Lula da Silva. The contents of the letter were not revealed, and the government did not comment on Silva's reaction.
France and Brazil have publicly criticized the proposal of a war against Iraq.
On Tuesday, Silva sent a letter to U.N. Secretary-General Kofi Annan suggesting a summit of world leaders interested in searching for a compromise solution.
In the letter, Silva said the discussion shouldn't be limited to leaders of countries on the 15-nation Security Council, of which Brazil is not a member.
The council is deeply divided over a resolution sponsored by the United States, Britain and Spain that would set a March 17 ultimatum for Saddam Hussein to prove Iraq is disarming.