On June 4, US President Donald Trump signed an executive decree imposing a complete ban on entry for people from 12 countries and restricting citizens of 7 other countries.
Citizens of countries banned from entering the US include Afghanistan, Chad, Congo, Guinea Xich Dao, Eritrea, Haiti, Iran, Libya, Myanmar, Somalia, Sudan and Yemen.
The decision, effective from June 9, also includes entry restrictions for people from Burundi, Cuba, Laos, Sierra Leone, Vietnam, Turkmenistan and Venezuela.
"I must act to protect the national security and national interests of the United States and the American people," Donald Trump stressed about the new decree.
In a video message released by the White House, President Trump said that the recent attack on an anti-Israel protest in Boulder, Colorado " highlighted the risks to our country because foreign citizens are not thoroughly screened upon entry".
The president noted that millions of illegal immigrants should not be in the US.
"We will not let what happened in Europe happen to the United States. Simply put, we cannot let a wave of free migration occur from any country without being able to check and screen the safety and reliable screening of those who seek to enter the US," Trump stressed.
"We will not allow those who want to harm us to enter our country," the US leader added.
During his first term in 2017, President Trump issued a ban on citizens of seven countries with a majority of Muslims entering the US, including Iran, Iraq, Libya, Turkey, Sudan, Syria and Yemen.
People from the above countries are banned from flights to the US or detained at US airports after landing. Those affected by the ban include tourists, those visiting friends and family, students and lecturers at US institutions and businessmen.