Google and Facebook have declined to give specific details on how its back to work plans will affect Irish employees.
The tech giants both told staff they would need to be vaccinated to return to work.
Previously, it has been clarified that such a move would not be allowed in Ireland.
In an email to its 130,000 global staff, Google chief executive Sundar Pichai said workers returning to the company's US offices in the coming weeks would need to be vaccinated, with the policy expanding "to other regions in the coming months".
In a separate update issued to its own staff, Facebook also said vaccination would be a requirement for staff returning to offices.
However, the situation for staff of both companies in Ireland is less clear.
A spokesperson for Google said the company had "nothing specific to share on Ireland plans" outside the details already outlined by Pichai, in which he wrote: "We’re rolling this policy out in the US in the coming weeks and will expand to other regions in the coming months. The implementation will vary according to local conditions and regulations, and will not apply until vaccines are widely available in your area."
Similarly, a spokesperson for Facebook here, said: "We don’t have an update for Ireland as our return to office plans are dependent on Government guidance and at the moment our policy is to work from home."
The spokesperson also quoted Lori Goler, vice president of human resources and recruiting at Facebook, who said "how we implement this policy in our international offices will depend on local conditions and regulations when we open”.
Irish employees could be returning to the officer sooner rather than later.
Taoiseach Micheál Martin has said it could be six weeks before Covid-19 restrictions are further loosened, with his Government colleague Eamon Ryan signalling a likely return to offices for workers from September.
Mr Martin said the Government would reassess in six weeks whether restrictions could be eased, adding there were "still unknowns out there and uncertainties" in respect of the Delta variant.
However, Transport Minister Eamon Ryan said he expected people to return to offices from September – something which may pose questions for workers at tech giants Google and Facebook, who have told its US staff they need to be vaccinated to return to office campuses.
The Taoiseach said he was "cautiously positive" about Ireland's fight against Covid-19, while Mr Ryan said of the prospect of a return to office-based working: "It won't be everyone back on the first of September, but I think we do need to start planning for that.
"It will be done probably on a hybrid basis, a staged basis and yes, I think that return to work is also part of this."