What we know and don't know about the travel ban implementation

The Supreme Court ruling leaves open a number of questions.

Here is a breakdown of what we know and don't know about the implementation.

What did the Supreme Court say?

What qualifies as a "bona fide" connection?

That includes foreign nationals with familial connections in the U.S., students who have already been admitted into an American university, workers with existing job offers in the U.S. and lecturers who have accepted invitations to conferences in the U.S.

"It leaves open a number of questions of interpretation and implementation," said Kate Shaw, ABC News' Supreme Court contributor. "I think it might lead to a lot of litigation over the summer about who exactly has enough of a connection to the U.S. to satisfy the Supreme Court's standard."

Who will determine a "bona fide" connection?

Once that is determined, State Department officials will share that guidance with consular officers around the world, but the Department of Justice is still working on the definition, Nuaert said.

Visa applications are reviewed and decided by a consular affairs officer in an embassy abroad. It is up to these public servants' discretion to grant or deny an applicant, and that will still be the case under the ruling -- they'll just have to factor in someone's "bona fide" connection now, too.

The term will have to be clearly defined before it is implemented "or there is a risk of inconsistent or even discriminatory practices at consulates and points of entry," he warned.

"Once defined, the definition will need to be communicated to those U.S. government personnel involved in the process of vetting those applying to travel to the U.S. from those countries in which the ban applies," Cohen said.

When does it go into effect?

"We will keep those traveling to the United States and partners in the travel industry informed as we implement the order in a professional, organized, and timely way," the statement said.

ABC News' Conor Finnegan contributed to this report.