UPDATE 4-Obama seeks $17 billion in U.S. budget savings

* Obama unveils details of budget he laid out in February

* Savings are just half a percent of $3.55 trillion budget

* Republican says spending cuts don't go far enough (Adds context, background)

By Caren Bohan and Jeff Mason

WASHINGTON, May 7 (Reuters) - President Barack Obama on Thursday proposed to wring $17 billion in savings from the fiscal 2010 budget as he sought to allay worries about soaring deficits and build support for a hefty domestic agenda.

Unveiling the detailed version of a budget blueprint he outlined in February, Obama offered a slim list of savings he will seek in programs from weapons systems to education to the cleanup of abandoned mines.

"We can no longer afford to spend as if deficits don't matter and waste is not our problem," Obama told reporters. "We can no longer afford to leave the hard choices for the next budget, the next administration or the next generation."

The proposals to trim 121 programs identified by the White House as wasteful or unnecessary amounted to only a half of 1 percent of the $3.55 trillion budget that Obama has submitted for the fiscal year that begins in October.

Of the $17 billion in budget savings the White House identified, about half were in the defense budget.