Developing countries will play an important role at the upcoming Group of 20 (G20) summit in Toronto to ensure global economic recovery, said a leading U.S. financial expert.

It's very important that emerging market countries have their voices heard at this meeting, Charles Dallara, managing director of the Washington-based Institute of International Finance (IIF), told Xinhua in a recent interview.

"No longer is it just about the United states or Europe's points. It should be about what China, Brazil, Indonesia and Mexico want."

He said that compared with advanced economies, China, India and Brazil all maintained very robust growth in the first half of this year, which made them more prominent on the world economic arena.

Dallara, a former U.S. assistant secretary of treasury for international affairs, said that the G20 Toronto meeting on June 26-27 will focus on two major topics -- growth and financial reform.

"The world economy is now facing a huge challenge from the fiscal belt-tightening of Europe. This is going to require other countries to help considering how they can sustain the world growth while Europe is going through this severe fiscal adjustment process," he said.

"It will be crucial at this G20 meeting, that the leaders of the United States, Europe, Japan and China try to find a coordinated approach to sustain the world growth."

On regulatory reform, Dallara said the IMF, which includes members of more than 400 world's leading banks and financial institutions, had been engaged on behalf of the private banking community in a very intense dialogue with global regulators, trying to strike a balance between a more stable system and a system that can still support a credit growth and economic growth.

In his views, the following questions are challenges the G20 leaders will face in Toronto.

"Are they serious about the global regulatory reform or they only give rhetorical support to this and go off and take individual, sometimes contradictory, national actions?"

Dallara said now the world is focusing on the new governance structure, the new context, the new leadership structure of G20. "The macroeconomic policy coordination needs to take place in G20 today."