In spite of controversy and violence that surrounded Sunday’s referendum for Catalonia, leader Carles Puigdemont says the Spanish region has won the right to statehood.
He said the door had been opened to a unilateral declaration of independence.
Catalan officials later said 90% of those who voted backed independence in Sunday’s vote. The turnout was 42.3%.
Spain’s constitutional court had declared the poll illegal and hundreds of people were injured as police used force to try to block voting.
Officers seized ballot papers and boxes at polling stations.
“With this day of hope and suffering, the citizens of Catalonia have won the right to an independent state in the form a republic,” Mr Puigdemont said in a televised address flanked by other senior Catalan leaders.
“My government, in the next few days will send the results of today’s vote to the Catalan parliament, where the sovereignty of our people lies, so that it can act in accordance with the law of the referendum.”
He said the European Union could no longer “continue to look the other way”.
In another development, more than 40 trade unions and Catalan associations called a region-wide strike on Tuesday due to “the grave violation of rights and freedoms”.
Earlier, as voting ended, Spanish Prime Minister Mariano Rajoy said Catalans had been fooled into taking part in an illegal vote. He called it a “mockery” of democracy.
“At this hour I can tell you in the strongest terms what you already know and what we have seen throughout this day. There has not been a referendum on self-determination in Catalonia,” he said.
Large crowds of independence supporters gathered in the centre of the regional capital Barcelona on Sunday evening, waving flags and singing the Catalan anthem.
Anti-independence protesters have also held rallies in Barcelona and other Spanish cities.