Defense Secretary Robert Gates says he doesn't see any immediate need to bulk up the military response to piracy on the high seas. Gates adds, however, that those decisions are being made moment by moment.

Gates is in Alabama on Tuesday to hear from future military leaders as he tries to sell his new $534 billion budget plan. He says his budget focuses on what those future warriors will need for the kinds of wars the United States is fighting now.

Gates says the precision work displayed by Navy SEAL snipers during the Somali pirate hostage rescue on Sunday shows the importance of proper and targeted training for the military.

The comments came as Somali pirates, undeterred by U.S. and French hostage rescues that killed five bandits, brazenly hijacked four more ships in the Gulf of Aden, the waterway at the center of the world's fight against piracy.

Pirates have vowed to retaliate for deaths of their colleagues � and the top U.S. military officer said Tuesday he takes those comments seriously. But Adm. Michael Mullen, chairman of the Joint Chiefs of Staff, told ABC's "Good Morning America" that "we're very well prepared to deal with anything like that."

Still, despite Mullen's confident statement and President Barack Obama's warning Monday, pirates captured two more nautical trophies Tuesday to match the two ships they seized a day or two earlier.

NATO spokeswoman Shona Lowe said the MV Sea Horse, a Lebanese-owned cargo ship, was attacked and captured Tuesday by pirates in three or four speedboats. She had no further information.

That hijacking came only hours after the Greek-managed MV Irene E.M. was seized in a rare overnight attack by pirates.

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In addition, Somali pirates also hijacked two Egyptian fishing boats in the Gulf of Aden off Somalia's northern coast, which maritime officials said had a total of 36 crew. It was not exactly clear if those ships were hijacked Monday or Sunday.

The Gulf of Aden, which links the Suez Canal and the Red Sea to the Indian Ocean, is one of the world's busiest and most vital shipping lanes, crossed by over 20,000 ships each year.

A flotilla of warships from nearly a dozen countries has patrolled the Gulf of Aden and nearby Indian Ocean waters for months. They have halted many attacks on ships this year, but say the area is so vast they can't stop all hijackings.

Choong said pirate attacks this year had risen to 78, with 19 of those ships hijacked and 17 vessels with over 300 crew still in pirates' hands. Each boat carries the potential of a million-dollar ransom.

The latest seizures come after Navy SEAL snipers rescued American ship captain Richard Phillips on Sunday by killing three young pirates who held him captive in a drifting lifeboat for five days. A fourth pirate surrendered after seeking medical attention for a wound he received in trying to take over Phillips' vessel, the Maersk Alabama.

Phillips on Tuesday was aboard a Navy vessel at an undisclosed location, Christensen said. He was initially taken aboard the Norfolk, Va.-based USS Bainbridge and then flown to the San Diego-based USS Boxer for a medical exam.

In Washington, Obama appeared to move the piracy issue higher on his agenda, vowing the United States would work with nations around the world to fight the problem.

"I want to be very clear that we are resolved to halt the rise of piracy in that region and to achieve that goal, we're going to have to continue to work with our partners to prevent future attacks," Obama said at a news conference Monday.