International Monetary Fund chief Rodrigo Rato on Thursday warned against the rising protectionist sentiment, which he described will pose a threat to the global economy.

"There is also a shared responsibility among all countries, but in particular larger economies, both industrialized and developing economies, to bring the Doha Round to a successful conclusion," he told a press conference.

This move would be "most important step to limit the risks of protectionism," he add.

As to the world economy forecast, he noted that the downside risks to the world economy are "less now than" they only a few months ago.

"Part of this change is because declining oil prices over the last few months relative to their highs of last summer have eased inflation, and that has reduced the risk to growth," he said.

But he also warned the world leadership should not be complacent.

"We have living through an extended period of benign financial conditions and low volatility, but recent market turbulences has reminded us that downside risks are still present," he said.

The IMF reported on Wednesday that the world economy is expected to grow robustly by 4.9 percent in both 2007 and 2008, but the United States may expand only 2.2 percent this year, the weakest growth in five years.