"Europe is moving resolutely towards an economic government of the eurozone," he told South Korean business chiefs at a seminar in Seoul.
Sunday's European Union summit would be a "decisive meeting", he said, although another summit is already planned for Wednesday as the eurozone battles to prevent Greece's problems from spilling over more widely.
Fillon said the crisis had exposed the "oversights" in the continent's monetary union, and that the world economy and governance was approaching a "moment of truth".
But he stressed: "Today Europe is faced with a new challenge. As she has always done in the past, she will overcome the tests and emerge strengthened.
"I encourage you to have confidence in Europe," Fillon told members of the French-Korean chamber of commerce and other Korean business leaders, ahead of a weekend visit to Japan.
EU ministers were to begin pre-summit talks Friday, amid hopes the leaders will agree to strengthen Europe's financial rescue facility and to recapitalise banks.
But rifts over how to solve the eurozone debt crisis which threatens the world economy have forced the 17-nation zone to call a fresh summit next Wednesday.
Fillon, the first French prime minister to visit South Korea in 20 years, started his schedule with a visit to the National Cemetery in Seoul.
He later met his counterpart Kim Hwang-Sik Friday for talks focusing on trade and investment links, and he will go on to Japan Saturday.