WASHINGTON – The Navy submitted a plan Tuesday for reversing the decline in the size of the U.S. fleet, expanding from 281 ships this year to 313 within several years, though the number of aircraft carriers would drop by one, to 11.

“We need to stop getting smaller,” Adm. Mike Mullen, the chief of naval operations, told a Pentagon news conference.

The Navy fleet has been shrinking for many years, and Mullen, who took over as chief last July, said that trend must be reversed if the service is to meet the demands of the global war on terrorism and other missions.

The plan submitted to Congress would require raising the Navy shipbuilding budget from $9.5 billion proposed in the 2007 budget that President Bush sent to Congress on Monday to an average of about $13.5 billion a year starting in 2008.

His plans calls for building 51 ships at a combined cost of $66.3 billion over the coming five years.

Sen. Olympia J. Snowe, R-Maine, whose state has both the Bath Iron Works shipyard and the Portsmouth Naval Shipyard, said she was pleased with the plan.

“Now that the Navy has identified a course of action, their charge will be to stay the course over the coming years with the necessary budgets and requisite industrial base that will truly reflect their commitment,” Snowe said. “After all, full funding of this plan is crucial to its ultimate success.”

Mullen said he may have to reduce spending on new Navy aircraft in the future to find the extra money for ships, which he described as the biggest challenge he faces as his service’s uniformed leader.

This year the Navy is scheduled to bring 14 new ships into the fleet while retiring 12. The net gain of two will increase the total number to 283 and end a string of annual declines that began in 1990 when Bush’s father was president. The fleet peaked at 594 ships in 1987 and has dropped nearly every year since.

Mullen’s plan calls for taking the aircraft carrier USS John F. Kennedy out of the fleet – a move the Navy proposed last year but was rejected by the Congress, which passed legislation requiring the Navy to keep the carrier fleet at 12 ships.

Mullen said he hoped to get that legislation changed “as soon as possible.”

The report to Congress said that while the Navy would like to expand the fleet, “the existing inventory of naval ships is more than adequate for the challenges we face today.” For the future, however, an anticipated “evolution of opposing navies throughout the world” makes it important to expand the U.S. fleet, it said.

On Capitol Hill, members of the Senate Armed Services Committee expressed worry about the size of the fleet.

Sen. John Warner, R-Va., whose states includes the enormous Norfolk Naval Shipyard at Portsmouth, said Mullen recently testified that if the Navy stayed on its current course, the number of ships in the fleet would slip below 250.

“A fleet of this small size may well jeopardize the Navy’s mission to meet its … requirements and the financial viability of the vital shipbuilding industrial base,” Warner said. He spoke during a hearing at which Defense Secretary Donald H. Rumsfeld outlined the 2007 Pentagon budget proposal.

In his news conference, Mullen also forecast that the number of sailors, Navy SEAL commandos and other Navy personnel in Iraq would expand this year. There currently are just under 4,000 in the country, he said, out of a total U.S. force of about 138,000.

Mullen said he expected Navy personnel to be called on to do more medical and security duties in Iraq, including taking lead responsibility for security at a new detention center in Iraq called Fort Suse.