The head of the International Monetary Fund says the global economy has entered a "dangerous phase" in which advanced economies risk slipping into a new recession that also would hurt developing nations.

IMF Managing Director Christine Lagarde said Thursday, in her first major speech in Washington since taking the post in June, weak growth and huge debts are holding back demand, investment and job creation.

Speaking at a forum of Woodrow Wilson International Center for Scholars, Lagarde said that if advanced economies enter their second recession since 2008, emerging markets will be pulled down with them. She said a lack of political determination in advanced economies to fix debt problems is making the situation worse.

Lagarde called on international leaders to take the same kind of urgent, collective action that they used to address the global financial crisis in early 2009. She said she was "very reassured" by a German-French statement that debt-ridden Greece must remain a part of the 17-nation eurozone.

Lagarde said she also welcomes U.S. President Barack Obama's recent proposals to stimulate economic growth and employment in the United States, the world's biggest economy.