The White House on Thursday said that the U.S. is strongly considering requiring foreign visitors to be fully vaccinated against COVID-19 but that there has not been a final decision on whether such a requirement will be adopted.

“That is certainly under strong consideration, but it is under a policy process review right now that I won’t get ahead of myself,” White House press secretary Jen Psaki told reporters at a briefing.

White House coronavirus response coordinator Jeff Zients on Thursday also said no decision has been made about how to reopen international travel and suggested other options were being considered beyond requiring foreign travelers to have vaccinations.

"That's one of the paths that's being looked at and considered, but there are alternative paths being looked at, at the same time," Zients told reporters during a coronavirus briefing. 

The comments represented a shift from guidance that a White House official provided a day prior. The official told The Hill that interagency working groups are working to develop a plan “for a consistent and safe international travel policy, in order to have a new system ready for when we can reopen travel.”

“This includes a phased approach that over time will mean, with limited exceptions, that foreign nationals traveling to the United States (from all countries) need to be fully vaccinated,” the official said.

Reuters first reported that the Biden administration is developing a plan to require foreign visitors to have COVID-19 vaccinations. There was not an indication on Wednesday that requiring vaccinations was among a handful of options being considered, or that the ultimate goal was not definitively to require vaccinations.

Asked to expand on the options that Zients alluded to, Psaki declined to offer more specifics.

“While there hasn’t been a final decision made, how the interagency groups are looking at this is with the objective of taking steps that will return international travel at a moment when it’s appropriate. Right now, we’re not at that point because of the rise of the delta variant but we want to have a process in place for when we hit that moment,” Psaki said.

Psaki said that it is important that the guidelines are clear, equitable, and that they do not conflict with one another.

It’s unclear precisely when the U.S. will lift restrictions on travel from Mexico, Canada, Europe and other countries. The White House said in late July that it would keep restrictions in place, citing the rise of the delta variant.