Italy's cabinet has passed an emergency decree targeting migrant rescue boats.
The decision came hours before right-wing interior minister Matteo Salvini announced the closure of a reception centre for asylum seekers in Sicily.
The decree will levy fines of between €10,000 (£8,900; $11,300) and €50,000 on ships entering Italian waters without permission.
Since the populist government took power a year ago, Mr Salvini has tried to stop migrants reaching Italy.
Ports have been closed to rescue boats.
Now Italy's ruling League and Five Star parties want to stop NGO boats entering Italian waters.
MSF and SOS Mediterranee said migrants were now almost four times more likely to die compared with last year.
"The lack of humanitarian vessels in the Central Mediterranean during this period should put to rest the unfounded allegation of a 'pull factor'," said Frédéric Penard of SOS Mediterranee.