The U.S. Homeland Security secretary says American officials have “no specific credible intelligence” about a potential threat from a Paris-type attack directed at the United States.

Jeh Johnson says authorities always have concerns about “potential copycat acts” and “home-born, home-grown violent extremism.” He tells NBC’s “Meet the Press” that Washington is “continually re-evaluating our security posture.”

Discussing the situation in Brussels, Johnson says American officials are in constant touch with law enforcement and intelligence authorities in Europe and elsewhere.

Johnson doesn’t want to freeze a program that lets foreigners enter the U.S. without visas from 38 countries for short stays. But he says he’s willing to work with U.S. lawmakers to see whether some “security enhancements” are needed in the visa-waiver program.

A(P)