Ryanair chief executive Michael O'Leary on Thursday said he could not rule out axing more flights, but added any additional cancellations would not be linked to ongoing pilot roster problems.

O'Leary told the Irish company's annual general meeting in Dublin that he "cannot guarantee there won't be further cancellations, but there won't be any further cancellations as a result of this rostering issue", a spokesman confirmed.

Any further grounding of planes would be linked to weather issues and strikes, which have also hampered also the no-frills airline giant recently, according to the spokesman.

Outspoken CEO O'Leary also expressed regret over the flight cancellations crisis that has plagued the carrier since late last week.

Ryanair has canned 2,100 flights to the end of October, as it struggles with landing planes on time, reportedly mainly owing to a shortage of pilots.

The cancellations had threatened to jeopardise the travel plans of 315,000 customers.

However, the airline revealed Wednesday that it has allocated replacement flights for more than half of those passengers.

Ryanair said Thursday it expects to have re-accommodated or refunded more than 95 percent of customers by the end of this week.

The group is scrapping 40 to 50 flights daily -- just short of two percent of its flying programme.

Ryanair has emailed affected passengers to advise them of flight changes, alternative flights, refunds and EU flight compensation law.

It estimates a total cost to the company of 25 million euros ($30 million) for the cancellations, which were sparked in part by an over-allocation of pilots' holidays during a relatively busy period.

O'Leary admitted at the start of the week that the scandal would have a "large reputational impact" on the group.