Britain should double the amount of refugees it takes in under resettlement programs, the United Nations has urged.
A senior official at the UN's refugee agency said accepting around 10,000 refugees a year would be a "step change" for the UK.
Volker Turk, assistant commissioner at the UN High Commission for Refugees, said there was a need for countries around the world to "step up" to address the crisis.
The Government has committed to take in 20,000 refugees by 2020 under a scheme set up to cover people fleeing the Syrian conflict.
Some 5,453 were granted humanitarian protection under the program in the year ending March 2017, alongside 3,000 vulnerable children and family members.
But Turk, who was in London for talks with ministers, said he hoped the Government's response would be "significantly" expanded after 2020: "It would be a doubling."
In an interview with the Press Association, Turk urged the Government to do more to end detention of asylum seekers; hit out at "irresponsible" rhetoric from Western politicians; and praised the response of British communities which have received refugees.
Turk said he wanted to see "significant numbers" of refugees offered the chance of a new life in the UK after 2020, with a resettlement program open to people fleeing trouble spots around the world, not just Syria.
After his talks with ministers he said: "We had good discussions about possible ideas about what can be done post-2020 and the Government is open to discussing this and to learn the lessons from what is ongoing at the moment.
"We hope very much that there will be a regular resettlement program by Britain past 2020 in significant numbers."
The aspiration was for it to cover 10,000 refugees or more, effectively doubling the current rate.
He added: "It would be a step change, it would not just be related to Syria. It would look at where the urgent situations are, to have a certain flexibility in responding to them.
"I think we have to be very honest about the need for countries to contribute and to step up."
Turk praised the response of communities which had already received refugees and said some rural areas had been "revived" by the new arrivals.
He said he was "very encouraged by the reaction in Britain, by communities at grassroots level".
"I'm so amazed when I hear about rural areas in Britain that actually they are so happy that people come to them and it almost revives parts of Britain," he said.
He compared it to the response of developing countries in the "global south", where there was often a "lot of solidarity" to refugees from other countries.
"I see this also in Britain and I don't think we hear enough about these positive examples," he said.
A "whole of society" approach was needed to address the challenges, he said.
"It's about attitudes, it's about engagement, it's about understanding towards the plight of people who end up - because of conflict, because of war, because of persecution - in a situation of distress.
"Britain has a long history of asylum and sanctuary. That tradition is absolutely key and it will involve whole communities."
But, he added: "You have the impression that some of the negativity is amplified but we forget about all the positive things that are happening."
Asked if some of the rhetoric used by some politicians was unhelpful, he said: "In the industrialised world more generally, sometimes what we see and what we notice is that emotionally-charged subjects are used for short-term political games.
"In some ways, from the perspective of fairness, from the perspective of the rule of law, from the perspective of how societies have to deal with phenomena that exist, that's irresponsible."
He added: "I think it's an appeal to everyone who works in this area to come back to this voice of reason within, sometimes, very high emotions."
The UNHCR has previously criticised the use of detention in the asylum system, and Turk said the agency was working with the Government on alternatives.
"There was a lot of agreement that we need to look at efficiency and fairness," he said.
"We want to work with the Government on alternatives to detention. Detention has been an issue for us - not just here but in other countries as well. "
He added that "we need to work more on family reunification issues" because family members seeking to join relatives was one of the causes of irregular migration.