The United States and Britain raced supplies and personnel to Russia early Saturday in an effort to rescue seven Russian sailors stuck in a crippled mini-submarine deep in the Pacific Ocean.

Adm. Viktor Fyodorov (search), the commander of the Russian Pacific Fleet, said rescuers were hoping to tow the vessel into shallower waters, where divers could be sent to the crewmen.

Meanwhile, A British military plane and a U.S. Air Force jet carrying remote-controlled underwater robots took off for the disaster scene off the Kamchatka Peninsula (search), in Russia's Far East.

The AS-28 naval sub, which has a limited oxygen supply that authorities fear might run out before rescue is possible, became stuck Thursday when it caught on an underwater antenna. The sub is about 600 feet below the Pacific's surface.

Moscow asked for outside assistance within hours of news breaking about the sub's plight — a speedy request that was a marked change since the Kursk (search) nuclear submarine disaster in 2000, when Russian officials waited until hope was all but exhausted. All 118 died aboard the Kursk.

If estimates that there was enough oxygen in the sub to keep the sailors alive for 24 hours hold true, both the U.S. and British rescue teams could arrive on time. But accounts of the oxygen supply have varied.

Fyodorov said early Saturday that there was oxygen for "at least 18 hours," a distinctly less optimistic statement than his earlier assertion that the air would last into Monday. Later Saturday, however, news agencies quoted him as saying there was air for "more than 24 hours."

"The situation is not simple. I don't want to overdramatize the situation, but also at the same time, I don't want to say it is absolutely, so to speak, easy and momentarily resolvable," Fyodorov said in comments televised on NTV.

The confusion over the air supply darkly echoed the sinking of the Kursk almost exactly five years ago. That disaster shocked Russians and deeply embarrassed the country by demonstrating how Russia's once-mighty navy had deteriorated as funding dried up following the 1991 Soviet collapse.

The new crisis is also highly embarrassing for Russia, which will hold an unprecedented joint military exercise with China later this month, including the use of submarines to settle an imaginary conflict in a foreign land. In the exercise, Russia is to field a naval squadron and 17 long-haul aircraft.

Navy spokesman Capt. Igor Dygalo told The Associated Press that rescuers had managed to move the sub about 60 yards toward shore. Fyodotov, however, was quoted by Russian news agencies as saying that the process was taking too long and rescuers would try to attach a tow line.

The rescue effort underscores that promises by President Vladimir Putin (search) to improve the navy's equipment have apparently had little effect. Authorities initially said a mini-sub would be sent to try to aid the stranded one, but the navy later said it was not equipped to go that deep.

Putin was criticized for his slow response to the Kursk crisis and reluctance to accept foreign assistance. By early Saturday, Putin had made no public comment on the latest sinking.

The sailors were in contact with authorities and were not hurt, Pacific Fleet spokesman Capt. Alexander Kosolapov said. Their mini-submarine was trapped in Beryozovaya Bay, about 45 miles south of Petropavlovsk-Kamchatsky, the capital of the peninsular region in Russia's far east.

The United States and Britain sent unmanned underwater rescue vehicles called Super Scorpios, and Japanese ships also rushed to the area. It was the first time since the World War II era that a U.S. military plane has been allowed to fly to the peninsula, home to numerous Russian military facilities.

Military experts told FOX News that in this emergency, time was of the essence.

"This is a race against time, literally," said Chuck Nash, a retired U.S. Navy captain and a FOX News military analyst. "They're sitting in the dark. They're 600 feet under the water. They know better than anyone what their condition is because they're rescuers themselves."

John Dalton, a former secretary of the U.S. Navy, told FOX News that the Navy is doing what sailors have done for centuries when other sailors are in trouble — race to help. But unlike sailors from the past, today they have access to high-tech tools.

"The Super Scorpio is a remotely operated vehicle ... It's got two manipulators that are capable of lifting 250 pounds each so it has the ability to assist in this situation if it can get there in time," Dalton said.

The flight from Naval Air Station North Island near San Diego to Petropavlovsk on Russia's eastern coast was expected to take 10 to 12 hours. The Scorpios and their equipment will then have to be loaded aboard a vessel and taken to the stricken mini-sub's location.

"We're the 911 force for submarine rescue," said Navy Capt. Russell Ervin, a reserve with Deep Submergence Unit 5. "In our business, minutes count."

The British Scorpio, being carried on a Royal Air Force C-17 transport plane, was expected to arrive at Petropavlovsk-Kamchatsky at about 7 p.m. Saturday local time, or 2 a.m. EDT. The U.S. plane was expected to land about 10:30 p.m. local time, or 5:30 a.m. EDT.

The mini-sub, which became disabled after it was launched from a ship in a combat training exercise, was too deep to allow the sailors to swim to the surface on their own or for divers to reach it, Russian officials said.

Although the Russian navy reportedly ended its deep-sea diving training programs a decade ago because of funding shortages, it does have a device called the Kolokolchik, essentially an updated diving bell, that can be used for some underwater rescues.

However, the mini-sub lies so deep that the device apparently would be useless.

U.S. divers, presumably with better equipment, rushed to the scene to help if necessary. In Belle Chasse, La., a marine services company sent sophisticated deep sea diving suits and a diving crew on board a military plane.

The Japanese ships were not expected to arrive until early next week.

Dygalo, the navy spokesman, initially said on state-run Rossiya television that the sub got trapped when its propeller became entangled in a fishing net Thursday. But Fyodorov later said the sub was stuck on an antenna, and Dygalo described the antenna as a "Pacific Fleet coastal infrastructure object."

The trapped AS-28, which looks like a small submarine, was built in 1989. It is about 44 feet long and more than 18 feet high. A vessel of the same type was used in the rescue efforts that followed the Kursk disaster.

Since Soviet times, the Kamchatka Peninsula has housed several major submarine bases and numerous other military facilities, and large areas of it remain closed to outsiders.

Despite strong criticism for Putin's response to the Kursk disaster, he was re-elected in 2004 and his supporters command an overwhelming majority in parliament, making the political fallout of the latest sinking likely minimal.

The Associated Press contributed to this report.