The U.S administration has set new rules for visa applicants from six mainly Muslim countries and all refugees, requiring them to have a "close" relative in the United States or a formal relationship to a U.S. organization.
The guidelines are due to come into effect at 8 p.m. Washington time on June 29.
They were issued after the Supreme Court on June 26 lifted lower court decisions blocking President Donald Trump's executive order suspending the U.S. refugee program and temporarily banning visitors from Iran, Libya, Somalia, Sudan, Syria, and Yemen.
But the court said the 90-day travel ban would not apply to visitors who have a "credible claim of a bona fide relationship with a person or entity in the United States." The 120-day ban on refugees is also being allowed to take effect on a similar, limited basis.
According to the new guidelines, people with a parent, spouse, child, son or daughter-in-law, or sibling in the United States will be able to enter the country, media reported, citing a State Department cable distributed to U.S. diplomatic posts.
However, the definition of "close" relationship excludes grandparents, grandchildren, aunts, uncles, nieces, nephews, cousins, brothers and sisters-in-law, and fiances.
Also exempt from the ban are those with ties to U.S. organizations, but such relationships must be formal, documented, and formed in the ordinary course, rather than for the purpose of evading" the executive order.
Those who already hold valid visas and dual citizens who travel on a passport from an unaffected country will be allowed entry.
Rights groups have been fighting Trump's executive order for the last five months, and lawyers warned that the new restrictions could open the door to legal challenges.
The president says his executive order is needed to stop terrorists entering the United States, but some critics consider the travel ban as a ban on Muslims.
The order was first signed in January but was blocked by court. A revised order was also halted by a judge before it was supposed to go into force in March.
The Supreme Court is to hear arguments in the case in October.
Copyright (c) 2015. RFE/RL, Inc. Reprinted with the permission of Radio Free Europe/Radio Liberty, 1201 Connecticut Ave NW, Ste 400, Washington DC 20036.