The White House on Friday offered a cautious welcome to the promise of fresh action by euro zone leaders during overnight talks to tackle their simmering debt crisis, but emphasized that the region will require ongoing steps to resolve its problems.

"We welcome the indications that euro area leaders made progress last night as they grapple with these challenges. We also ... note that these difficulties will not be resolved overnight and details remain to be worked out," said White House press secretary Jay Carney.

The European crisis has threatened the tepid U.S. economic recovery, together with President Barack Obama's own hopes for re-election on Nov. 6, as voters view sluggish growth and still high levels of unemployment as their most pressing concerns.

Euro zone leaders agreed on Friday to let their rescue fund inject aid directly into stricken banks from next year and intervene on bond markets to support troubled member states.

Carney reiterated Washington's longstanding position that it was in the U.S. national interest that the euro zone remain intact, and offered a measured endorsement of the deal struck in the early morning hours in Europe.

"It is encouraging the leaders are looking at ways to reduce immediate market stresses and undertake long-term reform and integration plans to promote growth and responsible fiscal policies," Carney told reporters traveling with Obama to Colorado to view forest fire damage.

However, he also voiced the wariness of many in financial markets who have watched previous European actions fall short during the two year old crisis, pointing out that there was still a long way to go before the region was out of the woods.

"This ... is an ongoing process of steps that need to be taken, and prior to last night Europeans have taken significant steps toward dealing with this. And I am sure there will be more steps taken in the future," Carney said.