Liverpool's Europa League semi-final first leg at Atletico Madrid will go ahead as planned on Thursday despite the problems with flights.
UEFA had earlier confirmed Fulham's semi-final in Hamburg would also take place.
The disruption caused to flights by the volcanic ash had led to fears the games would be postponed but UEFA say while they will continue to monitor the situation both matches are still scheduled to take place.
The announcement does not rule out the matches being postponed nearer the time if the travel situation continues to be such a problem.
UEFA said in a statement: "UEFA is continuing to closely monitor the travel situation throughout Europe and beyond, in an effort to confirm the staging of a number of matches that are due to take place this week in UEFA competitions.
"Regarding the UEFA Europa League semi-final first-leg matches scheduled for Thursday 22 April, between Club Atletico de Madrid and Liverpool FC, and Hamburg SV and Fulham FC, it is planned that both games will go ahead as normal.
"However, with the majority of airspace over Europe still closed and other forms of transport limited or fully booked, UEFA are in close contact with both English clubs on the travel options available to them.
"Further news and information on the exact travel possibilities for these away teams is expected over the next 24 hours."
Both the Champions League matches between Inter Milan and Barcelona and Bayern Munich and Lyon are going ahead this week with the visiting teams travelling overland by coach.
UEFA have postponed Sunday's Women's Champions League semi-final decider between Swedish side Umea IK and Lyon however.
