The Football Association of Wales has sold out Cardiff City Stadium for their World Cup play-off semi-final against Austria and potential final against Scotland or UkraineWales' World Cup play-off semi-final against Austria will go ahead this month despite the postponement of Scotland v Ukraine.
The winners of the two ties were due to face each other in Cardiff on 29 March for a place at Qatar 2022.
Fifa has accepted Ukraine's request to push back their tie in Glasgow following Russia's invasion of their country.
However, Wales' game with Austria will be staged as planned on 24 March.
"The FAW supports Fifa's decision in this matter and stands in solidarity with Ukraine and reiterates its condemnation for the use of force and the atrocities being committed by Russia," the Football Association of Wales said in a statement.
If Robert Page's side win, the Wales manager will then have to wait several months before knowing who they will face - and when - for a place in Qatar 2022 later this year.
Discussions are under way over a new date for Scotland versus Ukraine, with the Nations League window in June the most likely option.
The final could then also take place shortly after, though Wales are currently due to host both Belgium and the Netherlands this summer in addition to trips to Rotterdam and Poland.
"Alternative fixtures for teams in the March window are being explored by the relevant parties.," Fifa said in a statement.
"Similarly, the details of rescheduled fixtures will be announced in due course and the international match calendar window of June will be adapted as necessary for the teams concerned once these details have been finalised."
Last week FAW chief executive Noel Mooney said they would do whatever the could to show solidarity with Ukraine.
"We are a football family at the Football Association of Wales. We love football but we're also socially conscious as well," said Mooney.
"Like anybody else we're appalled and disgusted by what's happening right now with the Russian invasion of Ukraine."
The World Cup finals take place from 21 November to 18 December and the the draw for the tournament is scheduled for Friday, 1 April in Doha.
