With a major United Nations summit slated for Monday to tackle the global climate crisis, U.N. Secretary-General Antonio Guterres' message to member countries was clear: come up with plans, not more speeches.

But it remains unclear what — if anything — Japan will bring to the table at the U.N. Climate Action Summit, which is expected to draw over 60 world leaders.

Millions of people took to the streets on Friday in 117 countries to call on governments to do more to address the crisis. Environmental activists call the U.N. meeting the most important climate conference since the 2015 U.N. Paris meeting.