U.S. President Barack Obama on Wednesday said he was "deeply concerned" at the turmoil in the eurozone that has spooked global markets amid growing fears about Europe's debt crisis and anaemic growth.

"I am deeply concerned and I have been deeply concerned. I suspect I will be deeply concerned tomorrow and next week," he said at a press conference with Australian Prime Minister Julia Gillard in Canberra.

Obama spoke as European leaders struggle to address the continent's public debt woes, which continue to roil global markets and weigh on the euro.

While new prime ministers in debt-ridden Italy and Greece have offered investors hope they can solve their fiscal woes, traders remain nervous as their cost of borrowing hits new peaks.

Adding to the grim picture Tuesday were figures showing the 17-nation bloc grew just 0.2 percent in the third quarter.

In Asia on Wednesday, stock markets in Tokyo, Sydney, Seoul and Hong Kong were all lower while the euro lost further ground against the dollar.

Just over a week after he huddled with European leaders at the G20 summit in Cannes, France, Obama said the problem in Europe was one of "political will" to fix the fiscal turmoil that threatens to tip the world economy into recession.

"Until we put in place a concrete plan and structure that sends a clear signal to the markets that Europe is standing behind the euro and will do what it takes, we are going to continue to see the kinds of turmoil that we saw in the markets," Obama said.

German Chancellor Angela Merkel told a party congress this week that Europe was in its worst period since World War II, although she insisted the crisis could offer a chance to make the region stronger.

Obama acknowledged a genuine desire on the part of Merkel and French President Nicolas Sarkozy to solve the crisis, but warned the continent suffered from a complicated political structure.

"At this point, the larger European community has to stand behind the European project," Obama said.

"We have got an integrated world economy and what happens in Europe will have an impact on us," he added.

Obama's comments came a day after US Treasury Secretary Timothy Geithner said that Europeans were making incremental progress in addressing the crisis.

"I think they are gradually making progress," he said in response to a question about Europe at a public discussion organised in Washington by The Wall Street Journal.

"We hope they'll make progress more quickly" in the days and weeks to come, he added, as US authorities worry that spillover from the European crisis will hurt the still-recovering US economy.

The crisis "is hurting us already", he said.