The Trump administration has added seven countries, including five in Africa, to the list of nations whose passport holders are required to post bonds of up to $15,000 to apply for visas to enter the United States. Thirteen countries, all but two of them in Africa, are now on the list. It makes the process of obtaining a visa unaffordable for many but U.S. officials say it is an effective deterrent to prevent foreigners from overstaying their visas. The State Department last week quietly added Bhutan, Botswana, the Central African Republic, Guinea, Guinea-Bissau, Namibia and Turkmenistan to the list. Those designations took effect on Jan. 1. It's the latest effort by the Trump administration to tighten requirements for visa applicants.

he State Department is proposing requiring applicants for business and tourist visas to post a bond of up to $15,000 to apply to enter the United States. It's a move that may make the process unaffordable for many. In a notice to be published in the Federal Register on Tuesday, the department says it will start a 12-month pilot program under which people from countries deemed to have high overstay rates and deficient internal document security controls could be required to post bonds of $5,000, $10,000 or $15,000 when they apply for a visa. It says the countries affected will be listed once the program takes effect.