Singapore passport the most powerful in world

Singapore's passport is now the most powerful in the world, knocking off Japan, which had held the honor for five consecutive years, according to the International Air Transport Association. Hong Kong's passport ranked 17th.

Singapore passport holders can visit 192 of 227 travel destinations around the world visa-free. Germany, Italy, and Spain moved up to second place in the Henley Passport Index with straightaway access to 190 destinations.

Japan joined South Korea, Austria, Finland, France, Luxembourg and Sweden in third place with access to 189 destinations without a prior visa.

The United Kingdom appeared to have finally turned the corner after a six-year decline, jumping up two places to joint fourth along with Denmark, Ireland and the Netherlands. They have access to 188 places.

The United States continued its now decade-long slide down the index, plummeting a further two places to eighth with access to 184 destinations. The United Kingdom and United States jointly held first in 2014.

Hong Kong passport holders - tied with Andorra - can travel to 170 destinations.

Macau and Taiwan are among those tied for 31st, with access to 144 destinations. China is in joint 63rd with Bolivia, with 80 visa-free connections.

Afghanistan remained stuck at the bottom, with visa-free access to just 27 destinations, followed by Iraq (29) and Syria (30).

Christian Kaelin, chairman of Henley and Partners and the inventor of the passport index concept 18 years ago, said only eight countries worldwide have less visa-free access today than they did a decade ago.

"The United Arab Emirates has added an impressive 107 destinations to its visa-free score since 2013, resulting in a massive leap of 44 places in the ranking over the past 10 years from 56th to 12th position," Kaelin said.

"This is almost double the next biggest climber, Colombia, which has jumped 28 places to sit in 37th spot. Ukraine and China are also among the top 10 countries with the most improved rankings."

Henley and Partners also conducted research into the relationship between a country's openness to foreigners - how many nations it allows to cross its borders visa-free - and its own citizens' travel freedom.

The top 20 most open countries are all small island nations or African states, except for Cambodia. There are 12 completely open countries that offer visa-free or visa-on-arrival entry to all 198 passports in the world (not counting their own).

At the openness index's bottom, four scored zero, permitting no visa-free access for any passport: Afghanistan, North Korea, Papua New Guinea, and Turkmenistan.

They are followed by five that provide visa-free access to fewer than five other nationalities: Libya, Bhutan, Eritrea, Equatorial Guinea and India.

The top five with the smallest discrepancy between their access and their openness are Singapore, South Korea, Malaysia, Hong Kong and Barbados.