The leader of Cataloni has accused King Felipe VI of following Spain's central government's "catastrophic" policies towards the region.
In a televised speech late on Wednesday, regional president Carles Puigdemont condemned violence by police who tried to halt an independence referendum on Sunday that central authorities opposed.
He also again urged the Spanish government to accept mediation in what is one of the country's deepest political crisis in decades.
"We held the referendum amid an unprecedented repression and in the following days we will show our best face to apply the results of the referendum," Mr Puigdemont said.
The separatist leader also called the government of Prime Minister Mariano Rajoy "irresponsible" for not accepting mediation in the deadlock, and criticized King Felipe VI for following what he said were the government's "catastrophic" policies toward Catalonia.
"You have disappointed many Catalans," Mr Puigdemont told the king.
It comes after the Catalan president said the autonomous region will declare independence from Spain in a matter of days.
Mr Puigdemont will address the regional parliament on Monday to review the disputed vote - a session that his parliamentary supporters in the radical CUP group say they will consider the independence declaration.
Politicians in other parts of Spain and a handful of civil groups have offered to try to bridge the divide between the two sides, but Prime Minister Mariano Rajoy says no dialogue can take place outside of the country's constitution, which does not include provisions for a region to secede.
"Mr Puigdemont has been outside of the law for way too long," Mr Rajoy's deputy, Soraya Saenz de Santamaria, said, responding to the Catalan president's remarks in his televised address.
European leaders have sided with Spain and, amid fears that Catalonia's secession bid could find echoes elsewhere on the continent, the EU has so far refused to step in.