In a final communique, world leaders said they would take "all necessary measures" to protect the euro area.
Leaders said they welcomed Spain's plans to recapitalise its banks, according to the communique.
The talks were being held as Greece seeks to form a coalition government and Spain's borrowing costs soared.
Speaking to reporters at the end of the summit, President Obama said that European leaders recognised that "bold and decisive" action was needed to address Europe's debt crisis.
"What I have heard from European leaders during these discussions, they understand the stakes, they understand why it's important for them to take bold and decisive action, and I am confident they can meet those tests," he said.
President Obama said that while there was no "silver bullet" to solve Europe's crisis, "each step points to the fact that Europe is moving towards further integration rather than break-up".
"I am confident that over the next several weeks, Europe will paint a picture of where we need to go," he added.
As the summit came to a close the European leaders pledged to maintain stability in the eurozone and to work with the next Greek government towards reform and sustainability.
"Euro area members of the G20 will take all necessary measures to safeguard the integrity and stability of the area, improve the functioning of financial markets and break the feedback loop between sovereigns and banks," the joint statement said.
"We support the intention to consider concrete steps towards a more integrated financial architecture," it continued.
"The European Union members of the G20 are determined to move forward expeditiously on measures to support growth".