US President Barack Obama has said he is encouraged by European leaders' plans to tackle the eurozone crisis, as the G20 summit in Mexico ends.

In a final communiqué, world leaders said they would take "all necessary measures" to protect the euro area.

Leaders said they welcomed Spain's plans to recapitalize its banks, according to the communiqué.

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 recognized that "bold and decisive" action was needed to address Europe's debt crisis.