Catalonia's new pro-independence president says secession parties do not have enough parliamentary force to declare the powerful northeastern region's independence from Spain just yet but they will continue preparing for the promised new state.

Carles Puigdemont told Catalan TV3 television Thursday he was not ditching his party's pledge of secession but admitted it might need more time than the planned 18 months.

He said his government will prepare a new independence constitution he hopes will get majority backing in an eventual referendum. Fresh elections would follow.

Pro-independence groups won most seats in the region's September elections but failed to get a majority of the popular vote. Puigdemont was chosen as president in a last-minute deal to salvage the secession drive and avoid fresh elections.

Spain has ruled out separation.