Security at shipping ports around the U.S., including testing containers and vessels for biological and radiological hazards, is a top priority to preventing terrorism, U.S. Homeland Security Secretary John Kelly said Thursday.

As he rode aboard the Coast Guard Cutter Aspen, near the Port of Los Angeles, Kelly viewed an array of new equipment used to test for radiation and biological threats.

“The threat always changes, so we always have to be on top of that,” Kelly said as the vessel cruised through the Pacific Ocean off Southern California.

While he was aboard, members of the Coast Guard conducted a training demonstration, simulating the boarding of a ship with a radiological threat.

Members of the Coast Guard’s new California-based Maritime Safety and Security Team descended from helicopters with assault rifles and stormed the ship. Kelly watched from a deck above as they charged up stairwells and searched the ship as part of the exercise. Other crew members climbed up ladders from a smaller boat that pulled alongside.

“What they do, they do for you,” Kelly said.

As the vessel passed stacks of shipping containers at the Port of Los Angeles, Kelly said it is essential for law enforcement and Coast Guard personnel to constantly train and be prepared for any threats.

Kelly said he believes the current security levels at U.S. shipping ports is adequate, but his agency must continue to research new technology to keep up with changing threats. His biggest concern, he said, is contraband, including illegal drugs that are shipped in from other countries.

“It is all about protecting the nation and doing it as fast as we can so normal legal commerce, normal legal people can come in and out of the country and be inconvenienced at the minimum,” Kelly said.

(AP)