(Reuters) -- President Barack Obama assured Italian Prime Minister Mario Monti Thursday that the United States will do whatever it can to help stabilize the situation in the euro zone, which he said demanded a more muscular approach to fighting its debt crisis.

Something that we both agree on ... is the need for a stronger European firewall that will allow for a more stable path for repayment of debt, Obama told reporters after Oval Office talks with Monti.

Washington has stressed that Europe has the resources it needs to tackle the crisis, but requires a bailout package of such overwhelming size that it would deter speculators from attacking the region's debt markets.

European Union leaders gathering in Brussels on Thursday will discuss a Greek austerity deal to secure an international debt bailout, helping markets rally on the hope that this would head off a default by the euro zone's most indebted member.

Obama did not refer to developments in Athens in his brief remarks to reporters or spell out what help the United States might be ready to lend Europe.

With the United States facing tight budgets and modest growth of its own, U.S. official have made plain that this burden should be born mainly by the Europeans themselves.

Both leaders emphasized the importance of boosting European growth, which was important not only to Europe, but the entire world economy and to our economy back here, Obama said.

Obama also said that Monti had helped restore faith in Italy's ability to navigate its way out of a crushing debt crisis and build a stronger future.

Italy has a plan that takes seriously its fiscal responsibilities, but also emphasizes the need for structural reforms that can promote growth, Obama said.

(Reporting by Alister Bull; Editing by Xavier Briand)