After months of court battles and revisions, Donald Trump's travel ban is expected to be imposed tonight (29 June).
Earlier in the week, the Supreme Court permitted parts of the travel ban to be introduced which temporarily bans people from six mainly Muslim nations from entering the US.
According to CNN, from 8pm EST tonight, foreign nationals will require a "credible claim of bona fide relationship" to be able to get access to the US which could be from a school, job or spouse in the country.
Previous hotel bookings will not be able to circumvent the ban and access will be denied.
People from Libya, Syria, Iran, Somalia, Yemen and Sudan will be banned for 90 days. Refugees from any nation will be banned for 120 days. Those who already have gained access to visas will have them honoured.
Trump celebrated the Supreme Court ruling saying: "Today's unanimous Supreme Court decision is a clear victory for our national security. Today's ruling allows me to use an important tool for protecting our nation's homeland. I am also particularly gratified that the Supreme Court's decision was 9-0."
Pressure groups and advocacy organisations are set to be stationed at major airport including Washington's Dulles International and New York's JFK to observe how the measures are implemented.
The first travel ban was introduced in January leading to chaos at major airports across the US.
Courts around the country soon started blocking it, bringing the landmark policy to a halt. Trump then issued a watered-down version which was still turned down by courts.
The Supreme Court also agreed to hear the government's appeal against the lower courts which blocked the original and watered-down bans. The first arguments will be heard in the autumn.