Between January and May, 39,538 migrants arrived in Italy, compared to 43,000 for the whole of 2013, Alfano told a Schengen committee on Wednesday, according to a report on RAI News.
He said that while “caution is necessary on the estimates of arrivals in 2014”, migrant pressure “is very high” and is "continues to grow".
Earlier this month, the minister accused the European Union of failing to help after seventeen people drowned in a migrant boat shipwreck off the Sicilian coast, saying "the Mediterranean is not an Italian border but a European border".
He said that unless the EU provided more support, Italy would defy asylum rules and allow migrants to travel on to other countries in Europe.
Alfano also said on Wednesday that the government will pay “full attention” to the most vulnerable immigrants in Italy, such as the huge Chinese population living in the Tuscan textiles hub of Prato.
Prato is home to about 17,000 Chinese nationals, according to official data from 2010, but local sources say the real figure is closer to 50,000.
Alfano said there are 4,400 Chinese-owned businesses in the city, many of which are illegal and where staff work in dangerous conditions.
In December, seven people died in a Chinese-run clothes factory in Prato.
Alfano added that the government needed “decisive action” on firms that are “unfair competition to those that operate legally”.
But despite efforts clamp down on illegal businesses and dangerous conditions over the past fives years, shuttered warehouses often reopen elsewhere.
Meanwhile, on Wednesday French police forcibly expelled hundreds of migrants from camps in Calais.