Carles Puigdemont criticised Spain’s King Felipe VI for following the central government’s “catastrophic” policies towards Catalonia.
And he labelled Spain’s government “irresponsible” for not accepting mediation in the political crisis which erupted following the independence referendum at the weekend.
He said: “This moment calls for mediation. We have received various offers in the last hours and we will receive more.
“I will repeat it as many times as necessary: dialogue and agreement are part of the political culture of our people.
“However, the state has not given any positive answer to those offers.”
Spanish Prime Minister Mariano Rajoy’s office responded that if Catalonia wants talks, it “first needs to respect the law”.
Scores of people were injured on Sunday after police beat voters and protesters – dragging some of them away as they tried to take part in the referendum.
Hundreds of thousands of Catalans staged a rally on Tuesday during a general strike to protest against the violence.
Mr Puigdemont said: “We are following the democratic process and carrying out the will of the Catalan people.”
He insisted the process of declaring independence will take place within days, and accused King Felipe VI of disappointing many Catalans by urging the region to end its bid for independence.
“The king has adopted the government’s position and policies which have been disastrous with regard to Catalonia. He is deliberately ignoring millions of Catalans,” the politician added.
“I am sure that in the next few days we will show the best of our country when the institutions of Catalonia will have to apply the results of the referendum.”
The political crisis has raised fears the Spanish army could be moved in to enforce direct rule on the region from Madrid.
Madrid has the power to suspend the semi-autonomous status that Catalonia enjoys under Spain’s system of regional governments.
But that would likely spark further violent protests.
Stocks and bonds have tumbled in the country, with the Ibex index falling below 10,000 points for the first time since March 2015.
The nervous public mood prompted Spain’s economy minister to assure bank customers that their deposits are safe.
Following meetings in the regional parliament on Wednesday, pro-independence politicians called for a full session on Monday to debate the final results of the vote.
It had been suggested that Mr Puigdemont could declare Catalonia independent on Wednesday night, but that is now expected to take place following the parliamentary debate on Monday.
The Spanish government and courts have declared Sunday’s referendum illegal.
Just 42% of the electorate in Catalonia voted on Sunday, with 90% of those backing independence.
The vote was held without regular electoral lists or observers and polls indicate Catalans are split on the prospect of independence.
The region, home to 7.5 million people with their own language and cultural traditions, accounts for a fifth of Spain’s economy.
Claims for independence date back centuries, but have increased in recent years because of the economic crisis affecting the nation.
European Commission Vice President Frans Timmermans said on Wednesday that it was “time to talk”.
Speaking in an emergency debate in the European Parliament, he defended Spain’s right to “the proportionate use of force”.