UN Secretary-general Ban Ki- moon is expected to meet with world leaders at major global gatherings in Mexico and Brazil within the next two weeks, to discuss a range of issues including sustainable development and youth unemployment, a UN spokesman said here on Friday.

"The secretary-general will participate actively in the leaders ' meetings," UN spokesman Eduardo del Buey told reporters here at a daily news briefing.

"At the G20 summit the secretary-general will address important issues such as youth employment, (and) the need for innovative and inclusive financing to allow millions of people to get out of poverty," said del Buey, referring to the summit of the Group of 20 (G20) major world economies scheduled for June 18-19 in Los Cabos, Mexico.

The secretary-general is to leave New York for the summit on Monday, he noted.

"After participating in the G20 summit, the UN chief is scheduled to arrive in Brazil on Tuesday," he said, adding that in Brazil Ban would "open the (Rio+20) conference with (Brazilian) President Dilma Rousseff, and participate in a number of events -- including the meeting of Principals of the Secretary-General's High-Level Group on Sustainable Energy for All."

The Rio+20 conference, or the UN Conference on Sustainable Development, will be held in Rio de Janeiro, Brazil on June 20-22. It will mainly deal with such issues as sustainable development and climate change.

"Furthermore, the UN chief is set to meet with representatives of civil societies and the private sector, to encourage the international community to 'build the future we want,'" the spokesman added.