Around 160 Irish troops due to return home today from a peacekeeping mission in Kosovo are stranded in the Balkans.
The no-fly zone thrown up around Ireland and much of Europe has grounded a chartered plane sent out to bring back the soldiers.
The troops, mainly from the Eastern Brigade, will remain at the Irish unit at Camp Clarke, outside the Kosovan capital Pristina, until restrictions are lifted.
Captain Pat O'Connor, of the Defence Forces, said they were doing everything possible to get the mission back.
"We are trying to get the troops back as soon as we can," he said.
"Their families are waiting for them to come back but obviously we are constricted by the air space restrictions."
The mission, drawn mostly from battalions based in Dublin and Dundalk, have been winding down Irish operations in Kosovo over the past six months.
They are one of the last major deployments overseas, with the peace-enforcement mission in Chad expected to return in the summer.
Around 200 troops were based at Camp Clarke, in Lipljan, about 15km south of Pristina, where they still have access to "all possible comforts, including gym, canteen and cookhouse facilities", said the Defence Forces.
Around 160 of those will return to Dublin Airport on a chartered plane - currently grounded in Prague - as soon as Irish airspace is reopened.