Mr Mattarella, who guides the talks and has the job of naming the eventual prime minister, confirmed to local media that there had been "no progress" after concluding the second round of consultations.
However, he stressed the need to quickly form a new government given a series of pressing domestic and international issues like the tensions surrounding Syria, but said that he would wait a few days before deciding how to "end the deadlock".
Matteo Salvini's right-wing coalition, which includes Mr Berlusconi's Forza Italia (FI) party, is the largest group with 37 per cent.
The Five Star Movement (M5S) is Italy's largest single party after winning just under 33 per cent of the vote in the March 4 election.
Both have repeatedly said that they are ready to work together, but M5S leader Luigi Di Maio has demanded that Mr Salvini break with Mr Berlusconi.
The League only picked up 17 per cent of the vote on its own and Mr Salvini has refused to ditch his partner.
The 81-year-old broke ranks at the end of Mr Salvini's post-consultation speech to media on Thursday, blasting the M5S as not knowing "the ABCs of democracy".
Later Mr Di Maio asked Mr Berlusconi, who cannot hold public office due to a tax fraud conviction, to "step aside" so that he could start working with The League.
But on Friday morning, Mr Salvini stood his ground and warned of new elections if they didn't stop "bickering".
"The people will get fed up, I'll get fed up... either they pack it in or we vote," he said to national broadcaster Radio 1.
However, Mr Mattarella has other options other than new elections at his disposal, including a third round of consultations or giving an "exploratory mandate" to an individual within the parliament who could try to gain consensus from the squabbling parties.