By Andrea Shalal-Esa
WASHINGTON, July 12 (Reuters) - Four U.S. Republican lawmakers on Friday urged Defense Secretary Chuck Hagel to conduct another test of the missile defense system this year after last week's test failure, and to make development of a next-generation interceptor a top priority.
The lawmakers said the cause of the failed July 5 missile defense test was not yet clear, but they argued that President Barack Obama's cuts in spending on missile defense had reduced funding for needed tests and maintenance of the system.
Representatives Buck McKeon, chairman of the House Armed Services Committee and Mike Rogers, who heads the committee's strategic forces subcommittee, joined with Senator James Inhofe, the top Republican on the Senate Armed Services Committee and Senator Jeff Sessions, in signing the letter dated Friday.
The test failure comes at a time of growing concerns about missile development by North Korea, Iran and China. It follows years of budget reductions in missile defense by the Democratic administration that were sharply opposed by Republicans.
In Friday's letter, the Republican lawmakers faulted the Obama administration for rejecting ways to make the ground-based missile defense system more effective, cancelling a system that would have allowed multiple interceptors to be packed onto one rocket, and opposing efforts to fund an East Coast missile site.
A test last Friday of the only U.S. defense against long-range ballistic missiles failed, the third consecutive failure involving the interceptor system managed by Boeing Co . The military has tested the so-called ground-based midcourse defense system 16 times. It has succeeded eight times, with the last intercept in December 2008.
The Pentagon has said the test would not affect its decision to bolster the U.S. missile defense system by adding 14 new anti-missile interceptors at a cost of nearly $1 billion.
Hagel announced the move in March following threats by North Korea.
Given threats posed by North Korea and Iran, the Republican lawmakers said it was critical to conduct another intercept test as soon as practicable, and to begin work on a new so-called kill vehicle.
"We must continue to advance the national missile defense capability, even as we ensure the existing capability meets the highest levels of reliability," they told Hagel in the letter.
They also asked the head of the U.S. Missile Defense Agency to provide Congress with a plan for resolving the cause of the failure of the recent test, conducting a new intercept test and fielding a next-generation kill vehicle.
In Friday's test, a long-range ballistic missile target was launched from the U.S. Army's Reagan Test Site on Kwajalein Atoll, Republic of the Marshall Islands. The interceptor missile was launched from Vandenberg Air Force Base in California.