The comments came at a Bastille Day reception attended by O'Neill and French ambassador Pascal Maubert, and athletes from Wallis and Futuna, New Caledonia and Tahiti who competed in the Pacific Games.
Plans to open the diplomatic post come in the wake of a trade mission to Europe in June to drum up foreign investment in PNG, where a contingent of government and business leaders spoke at the UK-PNG Trade and Investment Fourm in London and a French Business Confederation breakfast in Paris.
At the time, O'Neill said companies like Total SA recognised PNG's investment potential.
"In my meeting with senior executives at Total SA, they reaffirmed their commitment to developing the third train of LNG in Papua New Guinea," he said.
O'Neill welcomed increased links with French companies, saying "more French businesses and people are living in PNG than ever before and this is likely to increase with the new LNG project."
He also said the technical knowledge and capacity building Total will bring into developing the Papua LNG project will continue to transform the economy.
"We see this as a major expression of confidence by France and its business in PNG and its economy, and we look forward to developing these opportunities together," he said.
Although resources is the dominant sector in PNG, the government hopes foreign capital could help the agriculture, fisheries, telecommunications and tourism industries.
O'Neill has also accepted an invitation to chair one of the meetings taking place during the Climate Change Conference in Paris later this year.