US President Barack Obama has said that if there were an 'uncontrolled spiral' and default in the euro zone it would be disastrous for the global economy.

'We think it would be disastrous for us to see an uncontrolled spiral and default in Europe, because that could trigger a whole range of other events,' Obama told a joint conference with German Chancellor Angela Merkel.

'We need to make sure that all the best ideas are brought on the problem.'

Obama also warned that Europe's debt crisis 'cannot be allowed' to threaten the broader global economy.

The debt crisis gripping countries such as Greece, Ireland and Portugal 'cannot be allowed to put the global economy at risk,' he said.

Greece is looking to other euro zone members to defuse its debt crisis, and Germany will play a key role in charting a solution, Obama said.

He said the United States would cooperate in efforts to address Greece's problems, including through the International Monetary Fund.

Merkel, in turn, said the euro zone had a common interest in ensuring its currency bloc is not endangered by the debt crisis and stressed she was confident that Washington would shoulder its fiscal responsibilities just as Europe is doing.

Obama also rejected concerns about a second US recession, amid a raft of poor data on US economic growth.

'I am not concerned about a double-dip recession,' he said.

'I'm concerned that the recovery we're on is not producing jobs as quickly as I wanted to happen,' he said, adding there was 'enormous work to do' to strengthen a US economic recovery.