The Spanish government is holding an emergency cabinet meeting and Prime Minister Mariano Rajoy is due to address parliament, a day after separatist leaders in Catalonia signed what they called a declaration of independence from Spain.
In a highly anticipated speech on October 10, regional President Carles Puigdemont said the landslide victory in the controversial October 1 referendum gave Catalonia the right to start the process of breaking from the rest of Spain.
But he proposed that the regional parliament "suspend the effects of the independence declaration to commence a dialogue."
Following his speech, the Catalan leader was the first to sign the document titled Declaration Of The Representatives Of Catalonia. Dozens of other separatist lawmakers signed it after him.
Madrid rejected the actions, which commentators say marks a critical point in a decade-long standoff between between Catalan separatists and Spain's central authorities.
Spanish Deputy Prime Minister Soraya Saenz de Santamaria said the Catalan leader "doesn't know where he is, where he is going, and with whom he wants to go."
Saenz de Santamaria said Puigdemont had put Catalonia "in the greatest level of uncertainty seen yet."
In Brussels, European Council President Donald Tusk pleaded directly with the Catalan leadership ahead of the speech to choose dialogue rather than a divisive call for independence.
In his remarks, Puigdemont was highly critical of the Spanish government's response to the referendum and the violent police reaction that left hundreds injured on voting day, but said Catalans have nothing against Spain or Spaniards.
Some 2.3 million Catalans -- about 43 percent of the electorate in the northeastern region -- voted in the referendum. Regional authorities say 90 percent were in favor and declared the results valid. Those who opposed the referendum had said they would boycott the vote.