The number of unaccompanied child migrants arriving in Kent has risen significantly in the past 12 months, the leader of the county council said.
Roger Gough said the number of young asylum seekers in the county had “doubled in a little more than a year”.
A reduction in lorries crossing the Channel because of coronavirus had led to a rise in child migrants making the journey in dinghies, he said.
Some 20 children arrived in small boats over the bank holiday weekend, he said.
When asylum-seeking children arrive unaccompanied in Kent, usually at Dover, they are passed into the care of the county council.
There were 450 child migrants in the council’s care at the end of April, compared with 257 in April 2019.
Mr Gough said stowing away on lorries had until recently been the “typical route for a young person,” but they were “to a large degree now coming in the boats”.
“What we are now seeing, particularly as you can imagine all the changes with lockdowns across Europe and a significant reduction in freight transport, is that actually the boats are becoming a route for those unaccompanied asylum-seeking children.”
The increase in new arrivals was putting “severe and growing pressure” on the council’s finances and social care services, he said.
Volunteers have said conditions in makeshift migrant camps in northern France have deteriorated during the pandemic, because of a reduction in charities working in the area.
Care4Calais volunteer Tia Bush said there were between 100 and 200 children living in Calais, who were mostly unaccompanied.
“The problem is the conditions have got so bad here with the virus that obviously people are more desperate to get to the UK,” she said.
“They are not safe here, so they have nothing to lose,” she said.
A Home Office spokesman said: “The government takes the welfare of unaccompanied children very seriously and provides funding to local authorities, including Kent, as a contribution to the cost of supporting unaccompanied children and those who leave care.
“This funding was significantly increased in May 2019.”