Spain's King Felipe VI also condemned the actions of the Catalan administration, saying the situation in Spain had become "very serious" and that those who had organised the vote were "outside the law". They demanded Catalan leaders "respect the law" by abandoning their efforts.
"This moment calls for mediation". Around 900 people were injured from clashes with riot police that day.
"Together with other bodies from civil society, we want to build bridges with dialogue that contribute to resolving the conflict in a peaceful and consensual fashion".
"We also reiterate the legal position held by this Commission as well as by its predecessors", the Commission said.
King Felipe's speech strongly accused the nationalists of undermining the Spanish constitution and intentionally breaking the law in their latest independence bid. "Far from that, he went one step further in his path to radicalization, isolation and defiance of institutions".
Why have some of Spain's European Union partners appeared keen to back Madrid? .
"But we have never received a positive response from the state", Puigdemont said.
Mireia Boya, a Catalan lawmaker from the pro-independence, left-wing Popular Unity Candidacy (CUP) party, said on Wednesday that a declaration of independence would follow a parliamentary session on Monday to evaluate the results of the referendum.
Such a move would severely test the government of Prime Minister Rajoy. It is amidst this context that Catalan nationalism has risen again.
The prospect of a rupture in Spain's young democracy - the dictatorship of Francisco Franco ended only in 1975 - has rattled business groups.
But the Spanish Constitution doesn't allow for an independence referendum.
The European Parliament is set to debate the crisis in Catalonia on Wednesday amid mounting criticism of a deafening silence in Brussels. The European Commission called the vote illegal but said it was a domestic matter for Spain. He told legislators in Brussels "all lines of communication must stay open". Barcelona is also the second largest and most populated municipality in Spain.
The agency said it expected to "resolve the CreditWatch within the next three months".
Thousands of extra national police were sent to the region and high-ranking Catalan officials involved in organizing the referendum were arrested.
Catalan authorities say around 900 people were injured and that of the almost 2.3 million votes counted, 90 percent voted in favor of an independent Catalan Republic.
She said: "The court's decision to suspend Monday's session before it had been formally convened "harms freedom of expression and the right of initiative of members of this parliament and shows once more how the courts are being used to solve political problems".