The Trump administration is suspending a visa-free travel program for Chinese nationals visiting a U.S. island territory after Republican lawmakers warned it could facilitate birth tourism and pose national security risks.Homeland Security Secretary Markwayne Mullin’s decision targets a Biden-era program that allowed prescreened Chinese nationals to visit the Northern Mariana Islands for up to 14 days without a visa.In a notice announcing the decision, the Department of Homeland Security cited concerns that the program could facilitate birth tourism, espionage and illegal onward travel to near...