US President Donald Trump said he looked forward to adding more countries to the travel ban list under which citizens of many countries are denied entry to the United States, while US media has revealed seven countries involved in this possible decision.

Trump spoke of his intention to expand the ban on Tuesday in an interview with the American "Wall Street Journal" on the sidelines of the World Economic Forum in Davos in Switzerland, but he declined to reveal the countries involved.

But the newspaper quoted officials who viewed the new list as saying that the target countries are Belarus, Eritrea, Kyrgyzstan, Myanmar, Nigeria, Sudan and Tanzania, noting that some countries will only face a ban on some types of visas.

The "Politico" news site said that the new list is not final and may be changed, but stated that a statement on this matter is expected soon, perhaps next Monday.

Trump issued the ban in its first version just one week after he took power in January 2017, claiming to protect Americans from terrorism.

The decision then targeted the citizens of seven Islamic countries - Iraq, Sudan, Iran, Libya, Somalia, Syria and Yemen - and caused chaos in the airports and massive protests.

After a series of appeals, judicial battles, and amendments, the US Supreme Court in 2018 upheld the third version of the ban, which imposes varying degrees of entry on citizens of seven countries - Iran, Libya, Somalia, Syria, Yemen, Venezuela, and North Korea.