Washington, D.C. ? President Bush said Sunday he appreciates the new British government’s “strong response” to terrorist threats in London and Scotland that prompted the United States to tighten airport security and add air marshals to overseas flights.

Bush remarked hours after his homeland security chief said the administration was satisfied with its current terrorism alert level following an attack at a Scottish airport and two foiled car bombs in London.

“I think given what we know now, we’re comfortable that we’re at the right posture,” Michael Chertoff said during a round of talk show appearances.

U.S. airports and mass transit systems are tightening security ahead of the Fourth of July holiday and more air marshals will travel on overseas flights.