President Bush's (search) plan for the Navy calls for buying fewer ships, while China (search), a potential security hot spot, is increasing and repositioning its fleet. It's a prospect that concerns some lawmakers.

The plan is contained in Bush's 2006 budget proposal, which Defense Secretary Donald H. Rumsfeld (search) on Thursday defended, saying the military was closely watching China's moves but that the U.S. Navy remains the pre-eminent fleet.

"The United States Navy ... is the Navy on the face of the Earth that is a true blue water navy," Rumsfeld told the Senate Armed Services Committee. "On the other hand, when one looks at trend lines, it is something that we have to think about."

The Pentagon says buying fewer ships than previously planned won't affect combat ability. Previous budgets envisioned purchasing six Virginia-class attack submarines, seven DD(X) destroyers and 10 San Antonio-class amphibious landing ships through 2011.

The 2006 budget calls for three submarines, five destroyers and nine landing ships. It also proposes eliminating one of the Navy's 12 aircraft carriers. Overall, Bush is proposing to increase the Pentagon's budget by $19 billion, to $419 billion next year. The budget calls for buying fewer planes, ships and submarines in favor of spending more on counterterrorism.

Republicans and Democrats argued that cutting back now could jeopardize the Navy's long-term domination of the seas, particularly in light of China's military improvements.

Lawmakers also worry that any reductions would cost them work and jobs at the nation's shipyards.

Republican Sen. Susan Collins, whose state of Maine is home to the Bath Iron Works, one of the Navy's largest ship builders, expressed her reservations to Rumsfeld.

"I recognize that our naval fleet still remains the most technologically advanced in the world. But the decreasing number of ships being procured, particularly in the light of the Chinese buildup, really concerns me," she said.

"Are you concerned about projections that the Chinese fleet may well surpass the American fleet in terms of numbers in just a decade's time?"

"Senator," Rumsfeld replied, "it is an issue that the department thinks about and is concerned about and is attentive to."

One of Rumsfeld's top aides, Douglas Feith, echoed the secretary's views in an appearance later Thursday before the Council on Foreign Relations, a private think tank.

Feith, the undersecretary of defense for policy, singled out China as among "important powers in the world," whose strategic choices will influence U.S. national security.

"Of the new powers that are rising ... the country that can be expected to have the greatest effect on international relations is China," Feith said.

China has invested heavily in its own defense in the past few years. Prohibited from buying U.S. and European arms under an embargo, Beijing purchased at least $13 billion worth of weapons from Russia between 1993 and 2003, according to the Stockholm International Peace Research Institute. China's arsenals now are stocked with Russian-made submarines, destroyers, supersonic fighters and anti-ship missiles, as well as weapons it increasingly is making on its own.

CIA Director Porter Goss told the Senate Intelligence Committee this week that China last year increased its ballistic missile forces and rolled out several new submarines.

"Improved Chinese capabilities threaten U.S. forces in the region," Goss said.

Kenneth Lieberthal, an expert on China at the Brookings Institution in Washington, said China was probably still two decades away from U.S. military capability.

"But its rate of improvement has really changed a lot in the past few years," Lieberthal said.

China is trying to persuade the European Union to lift the 15-year-old arms embargo so it can access European technology. Earlier this month, the House strongly condemned the European Union's plans to comply.

And, Rumsfeld has said, China is moving its naval vessels farther from its shores.

Rep. Randy Forbes, R-Va., told Rumsfeld during a House Armed Services Committee hearing on Wednesday that he recently returned from China with "a big concern" about the U.S. fleet after he witnessed China's naval buildup.

"We looked at their steel mills," Forbes said. "They're throwing out steel as fast as you can watch it; running it 24 hours a day."