Trump's controversial ban on visitors from six Muslim-majority countries expires Sundays, 90 days after it went into effect.
Shortly after the announcement, Trump tweeted: "Making America Safe is my number one priority. We will not admit those into our country we can not safely vet", Trump tweeted on Sunday evening. "The countries affected have "'inadequate' identity-management protocols, information-sharing practices, and risk factors", the White House said in a statement.
Officials had said they wanted the new rules to be both tough and targeted.
Restrictions vary by country, with some countries on the list facing a total ban on USA entry, while others will be prohibited from immigrating while being allowed to travel for school. They further advised restrictions will be phased in "over time", and that "the restrictions will not affect anyone who already holds a USA visa".
Individuals with that "bona fide" exception, such as a foreign grandparent of a USA citizen, can still apply for visas until October 18.
The new travel restrictions could include indefinite bans on entry until vetting procedures and security cooperation improves, officials said.
"This looks to be the Trump administration's third try to make good on an unconstitutional campaign promise to ban Muslims from the United States", ACLU Executive Director Anthony D. Romero said in a statement.
Sudan has been removed from the list after featuring in the President's initial travel ban.
A decision on that issue would be consequential not just for Trump but also future presidents who would be bound by it.
In a statement, the White House called the new restrictions a "critical step toward establishing an immigration system that protects Americans' safety and security in an era of risky terrorism and transnational crime", CNN reported.
The Supreme Court is due to hear oral arguments in the challenge to the March 6 order on October 10.
After a bomb partially exploded on a London subway last week, Trump once again called for a tougher ban.
As well as adding new countries to the ban, the new executive order broadens restrictions of people from the original list.
Critics have accused the president of overstepping his authority and violating the U.S. Constitution's protections against religious bias.
After losing challenges in appeals courts, on March 6 the White House unveiled a revised ban, excluding Iraq and exempting people who already had visas.