At least 140 children with serious health conditions are living on a Greek migrant camp without access to healthcare, it's been claimed.

Doctors Without Borders (MSF) says there are youngsters with epilepsy, diabetes and heart disease at Moria complex on the island of Lesbos.

"We see many children suffering from medical conditions such as diabetes, asthma, and heart disease who are forced to live in tents in abysmal, unhygienic conditions, with no access to the specialised medical care and medication they need," said Dr Hilde Vochten, MSF medical coordinator in Greece.

"MSF is in discussions with the Greek authorities to transfer children to the mainland for urgent medical care, but despite the fact that some children were screened, none have been transferred yet.

"The government's general unwillingness to find a swift, systematic solution for these children, including some babies, is outrageous—it harms their health and could lead to lifelong consequences or even death."

Moria has a capacity for 3,000 people but there are currently more than 19,000 people crammed onto the site, according to MSF.

Among them are more than a 1,000 unaccompanied migrant children. Human Rights Watch claims they are exposed to "inhuman and degrading living conditions".

“Hundreds of lone children on Lesbos are left to fend for themselves, sleeping on mats and cardboard boxes, exposed to worsening and dangerous weather conditions,” said Eva Cossé, Greece researcher at Human Rights Watch. “The Greek authorities need to urgently make sure these children are safe and cared for.”

''We are now creating right sick adults because they never had the chance to grow properly as children,'' warned MSF psychologist Grigoris Kavarnos.

Last week it emerged there had been a significant increase in the number of people making unauthorised entries into Europe from Turkey last year, according to the European Union’s border agency.

More than 82,000 migrants attempted to enter the EU from the eastern Mediterranean route in 2019, compared with 55,900 the year before.

This has put pressure on already overcrowded migrant camps on the Greek islands, which are on the frontline.

Last week local politicians travelled to Athens to ask the government to do more to address the overcrowding.

"We consider citizens' anxiety and indignation justified,'' said migration minister Notis Mitarakisafter the meeting. ``

"Our country is indeed dealing with a migration crisis and increased migration flows in 2019 put pressure on local communities."

Greece has been the first point of entry into the European Union for hundreds of thousands of people fleeing war or poverty at home, with most arriving on eastern Aegean islands from nearby Turkey.

Under a 2016 EU-Turkey deal, new arrivals must stay on the islands pending deportation back to Turkey unless they successfully apply for asylum in Greece. Only those deemed vulnerable can be transferred to the mainland.

Mitarakis said the government and the islands' officials agreed on current priorities, which are to reduce the number of new arrivals, ease overcrowding in the camps, speed up returns to Turkey, improve the asylum process and improve healthcare facilities on the islands.

The minister added he would be meeting the mayors and regional governor every two weeks.