US President Donald Trump's administration has significantly expanded the program under which citizens of some countries must pay a cash bond of $5,000 to $15,000 when applying for US B1/B2 (tourist and business) visas, Fox News reports.

This measure does not guarantee visa approval, but the bond can be returned if the applicant is denied or if he complies with the conditions of the visa and leaves the US on time.

The new rules are scheduled to take effect on January 21.

This policy, designed to reduce visa overstays and strengthen entry controls, has almost tripled the list of countries from which such bonds are required. It now includes 38 countries, most of them in Africa, as well as a few in Latin America and Asia.

The aforesaid bond is just one of the requirements, along with a mandatory personal interview and extensive analysis of all applicants' social media accounts, reports AP.

This expansion of visa bond requirements is part of the Trump administration's broader immigration strategy aimed at tightening controls on entry to the US. Human rights activists and critics point out that such measures could make US visas financially unaffordable for many people, especially from low-income countries. However, US authorities argue that it helps reduce cases of illegal overstaying and increases visa compliance.