After a lengthy history lesson on the independence campaign, Puigdemont switched from Catalan to Spanish to announce that Catalonia had won the right to independence.
“Catalonia has earned the right to be an independent state and the right to be heard,” Puigdemont said.
“The ballots boxes said yes to independence, and this is the only language we understand.”
“I assume the mandate for Catalonia to become an independent State in the form of a republic,” he added, to a lengthy round of applause from the chamber.
Puigdemont said any declaration of independence would be suspended until a solution could be agreed.
No definite date was given, but he called for several weeks of dialogue.
There was speculation that he was about announce a unilateral declaration of independence from Spain following a disputed referendum.
But a session of the regional parliament was delayed by an hour, amid growing demands for him to drop plans to break away.
Reports say Catalan party leaders had a meeting before the session begins.
Catalan police have been posted outside the parliament in Barcelona, sealing off the grounds to the public.
A large pro-independence rally is currently taking place in the area.
Earlier, the mayor of Barcelona has urged Mr Puigdemont and Spanish Prime Minister Mariano Rajoy to “de-escalate” the crisis.
The Madrid government called on the Catalan leader “not to do anything irreversible, not to pursue a path of no return and not to make any unilateral independence declaration”.
And the president of the EU’s European Council has appealed to him to respect Spain’s constitutional order.
Source: bbc.com, CNN.com