These are the most valuable passports in the world

Unsplash/Annie Spratt

Singapore's passport provides access to more countries than any other.

The Trump administration has drawn controversy for its efforts to ban travel from Middle Eastern countries like Libya, Syria, and Yemen. Now, its policies may be coming back to bite American citizens.

Finance firm Arton Capital has placed the United States behind 18 countries in its most recent rankings of passport mobility, which measures the number of countries one can visit with a given nation's passport without obtaining a visa.

The United States is tied for sixth in this year's rankings, which marks a steep drop from 2015 when it held a number-one ranking with the United Kingdom. The decline has accelerated since Trump took office, as countries such as Turkey and the Central African Republic have ended their policies of visa-free travel from the United States.

You can see which countries have moved above the United States below. Countries are ranked according to Arton's "Visa-Free Score," with a higher score resulting in a higher ranking.