(Adds Cornyn's call for resignation, Reid's defense of general, details)
WASHINGTON May 6 Two Republican U.S. senators on Tuesday joined veterans groups in calling for Veterans Affairs Secretary Eric Shinseki to resign amid claims that up to 40 people died while waiting for treatment in the U.S. veterans' healthcare system.
Senator Jerry Moran of Kansas, said the Veterans Affairs Department needed a "true transformation ... from top to bottom."
"I ask the secretary to submit his resignation and I ask President (Barack) Obama to accept that resignation," Moran said on the Senate floor.
Assistant Senate Republican leader John Cornyn said: "The president needs to find a new leader to lead this organization out of the wilderness, and back to providing the service our veterans deserve."
But Senate Democratic Leader Harry Reid defended Shinseki, calling him "a fine man," and saying that allegations about the VA need to be investigated.
"Whether there's substance to it or not, I don't know, but it certainly doesn't call for the general to resign," Reid said. "He's been given a tremendous burden. We have millions of veterans who are coming back from Iraq and Afghanistan."
The calls for Shinseki's resignation came after the VA secretary put the director of a Phoenix hospital on indefinite leave last week as the department's inspector general probes whistleblowers' claims that up to 40 veterans may have died while waiting for medical appointments.
Two other hospital officials were also put on leave.
Veterans Affairs is the U.S. biggest healthcare system, including 1,700 hospitals, clinics and other facilities with nearly 9 million people enrolled.
The American Legion, the biggest U.S. veterans' group, and Concerned Veterans for America called on Monday for Shinseki, a former Army general twice wounded in Vietnam, to step down.
Representative Mike Coffman, a Colorado Republican and head of the House Veterans' Oversight and Investigations Subcommittee, also urged Shinseki to resign on Monday.
Cornyn, a Texas Republican, called on the Senate on Monday to hold hearings into the claims, which include a report by USA Today that a VA investigation showed clerks at a VA clinic in Colorado were told to falsify records to show faster treatment of patients.
Senator Jeff Flake, an Arizona Republican, also asked Shinseki on Monday to clarify the VA's investigation into the suspected lack of care.
Obama on Monday expressed support for Shinseki and the VA has defended his record.
Senator Bernie Sanders, an independent from Vermont and chairman of the Veterans' Affairs Committee in the Senate, has also pushed back on calls for Shinseki's resignation.
He said on Monday that firing him "doesn't get us any closer to the truth or solve problems that may exist." (Reporting by Ian Simpson; editing by G Crosse, Scott Malone and Cynthia Osterman)