MANILA - L Philippine President Rodrigo Duterte Tuesday declared communist rebels "terrorists", his spokesman said, weeks after cancelling peace talks with groups waging one of Asia's longest-running insurgencies.

In an attempt to boost negotiations, Duterte last year freed top rebel leaders from prison and met them at the presidential palace, but the peace process quickly soured after deadly attacks against soldiers and police angered the president.

Duterte signed an order Tuesday declaring two communist groups "terrorist organisations", but it would require court approval to go into effect, his spokesman Harry Roque told reporters.

The classification targets the Communist Party of the Philippines (CPP) and its 3,800-member armed wing, and the New People's Army (NPA), accusing them of "continued violent acts".