Updated

WASHINGTON -- A top military official says new warnings about insulated beverage containers are an example of federal officials trying to anticipate terror tactics.

Adm. James Winnefeld told The Associated Press Friday that the Transportation Security Administration is "always trying to think ahead." Winnefeld is the head of the U.S. Northern Command, which is charged with protecting the homeland.

TSA officials had said Thursday that in coming days, passengers flying within and to the U.S. may notice additional security measures related to insulated beverage containers such as thermoses.

Winnefeld says officials responsible for homeland security are always a bit more alert over the holiday season. He says there has been a lot of chatter online about potential terror activity, but nothing specific.

Meanwhile, President Obama's counterterrorism chief, John Brennan, held an inter-agency conference call Friday to review steps the government is taking to ensure vigilance, including enhanced security measures and coordination with foreign partners. Homeland Security Secretary Janet Napolitano and FBI Director Robert Mueller were among those on the call. The president is vacationing in Hawaii with his family.