Speaking in Parliament on Thursday, the UNHCR director for Europe Vincent Cochetel outlined new proposals for tackling the migrant crisis and also urged the EU to "reshape" its common asylum programme.
He told members of the Parliament's civil liberties committee, "These very specific proposals go beyond what the Commission has put forward, partly because it is felt that the Commission has not always taken into consideration what has been happening in 2015 and 2016."
This was a reference to the asylum/migrant crisis that has engulfed much of Europe, particularly countries like Greece, which has found itself inundated with people seeking refuge from Africa and elsewhere.
The official told MEPs that "part of the asylum system does not work" and that "lessons should be learned" from the crisis.
One recommendation from the UNHCR, he said, was for a "substantial reinforcement" of what he called "safe pathways" for migrants "who want to move legally to Europe.
"Such routes do not exist today but these would provide an alternative to the sort of irregular movements we have seen in the last couple of years."
He added, "The scenes we have seen, with the image of migrants moving across countries, have shocked many in Europe. Many were shaken by these images and we have to rebuild trust in the asylum system.
"But I have to tell you that it is not unlikely that we will see a similar influx in Europe in the coming years.
"This may not be what people want to hear but Europe should prepare itself for this. We do not want to see the scenes of 2015 and 2016, but my big concern is that Europe does not have a Plan B to deal with a repeat of the crisis."
Among the UNHCR recommendations is a proposal for a common registration system. Accelerated and simpler procedures for asylum determination are among other proposals he outlined during his presentation to the committee.