The US Supreme Court said it will review President Donald Trump's latest travel ban affecting citizens from six Muslim majority countries plus North Korea and Venezuela.
In what could prove decisive in a legal battle that has roiled the first year of the Trump administration, the high court will rule on whether the president exceeded his powers and engaged in religious discrimination in the third rendering of the ban.
Lower courts in California, Hawaii and other states have repeatedly ruled that Trump's order targets Muslims in violation of the US Constitution.
"We have always known this case would ultimately be decided by the United States Supreme Court," said state Attorney General Doug Chin of Hawaii, which has repeatedly fought the travel bans.
"This will be an important day for justice and the rule of law. We look forward to the Court hearing the case."
The conservative-tilting court last month rejected calls for a freeze on the ban, which targets visitors from Chad, Iran, Libya, Somalia, Syria and Yemen, allowing Trump to implement it while it was being challenged in lower courts.
The US administration has rewritten the ban twice, adding more national security justifications in the latest iteration in September and including citizens of North Korea and Venezuela to counter the argument the government was singling out Muslim countries.
Trump's initial travel ban, decreed a week after he took office, triggered chaos out at US airports, with travellers detained upon arrival, and nationwide protests against a measure seen as discriminatory - though Trump said it aimed to keep out extremists.
Court challenges have seized upon Trump's repeated comments against Muslims, starting with his campaign vow to ban them from entering the country, to make the case that they were the intended target.
The first ban was quickly blocked in court, as was a modified version removing Iraq from the list of countries.
Regarding the third version, critics noted that the United States welcomed no more than a handful of annual visitors from North Korea, and in Venezuela's case, the ban was made specific to a number of high-ranking officials in a government already facing US sanctions.
One key difference in the latest version of the ban was that it was open-ended, whereas the previous two versions were set for 90 days, ostensibly for the government to review security threats from the countries.
The Supreme Court will review those arguments, but also whether Trump has the executive power to order such a ban.