Thousands of Marines, sailors and soldiers headed Monday for the Persian Gulf region, shipping out from California, Georgia and Maryland as the buildup for a possible war with Iraq accelerated sharply.

“I’m worried. I’m also proud,” K.C. Lindberg said moments after saying goodbye to her son, a 23-year-old machinist’s mate in the Navy who set sail from San Diego on the USS Tarawa. “I’m going to miss him a whole lot, and we don’t know what’s ahead. But he’s going out there to protect you and me.”

President Bush has threatened to attack Iraq if it does not eliminate its weapons of mass destruction as required by U.N. resolutions adopted after the Iraqi invasion of Kuwait in 1990.

The Pentagon has indicated it plans to deploy as many as 250,000 soldiers in the Gulf region; at least 50,000 are already there.

More than 10,000 Army soldiers in Georgia were expected to leave Fort Benning and Fort Stewart in the next week. The troops are from the 3rd Infantry Division (Mechanized), which specializes in desert warfare and is expected to have all 17,000 soldiers and support staff in the region eventually.

Swirling snow fell in Baltimore as the Navy’s giant floating hospital ship USNS Comfort left for the Indian Ocean island of Diego Garcia. The 1,000-bed ship has 12 operating rooms and is equipped to handle troops injured in biological and chemical attacks.

In San Diego, 4,000 Marines and sailors set sail on a six-month voyage that will put them within striking distance of Iraq. Family members wiped away tears and waved to loved ones standing behind the rails of the USS Tarawa some 20 stories above the pier.

The ship, which should reach the gulf sometime next month, is carrying the 15th Marine Expeditionary Unit, which saw action in Afghanistan a year ago. Three members of the unit received Purple Hearts after they were wounded in a land mine explosion.

The Tarawa, bristling with six Harrier attack jets and a squadron of helicopters, is second in size only to an aircraft carrier.

In the Persian Gulf, it will join the USS Constellation, a carrier that earlier left San Diego with 8,000 sailors and Marines in a seven-ship battle group.