Leaders from the world's top economies on Thursday officially kicked off the two-day G20 summit in Seoul, heralding heated debate on ways to lead the global economy out of a downturn.

A two-hour working dinner was held late Thursday among leaders brought together here for the economic summit, with South Korean President Lee Myung-bak, who chairs the summit, officially declaring the opening of the talks.

During the two-hour working dinner at the National Museum of Korea in Seoul, titled "Global Economy and Framework I," Lee started off by introducing agenda items for discussions.

Managing director of the International Monetary Fund (IMF), Dominique Strauss-Kahn, briefed the leaders on the current status of the world economy, which prompted free discussions among the leaders.

Lee called on the leaders to use the Summit sessions to work toward a "meaningful" outcome, to offer direction and a vision for the global economy, and make more contributions to the global recovery through continued international cooperation.

Discussions at the working dinner will be followed up at Friday 's morning session under the title of "Global Economy and Framework II".