The Philippines is withdrawing from its cease-fire agreement with the country's communist rebels.
President Rodrigo Duterte told the country's troops Friday to get ready to fight.
The military says six soldiers have died in fresh fighting with the rebels.
General Eduardo Ano, Armed Forces of the Philippines chief of staff, welcomed the lifting of the cease-fire, saying, "We will go after the communists … and we will hit them hard."
Duterte's announcement came just two days after the communists announced their decision to end their self-declared truce.
The communists had demanded Duterte release 400 jailed guerrillas. Duterte called the demand "unreasonable."
The communist insurgency began in 1968. It is one of the longest-running insurrections in the world and has killed at least 30,000 people.
The two sides have engaged in peace negotiations brokered by Norway, with another round slated to begin in April.
The rebels said the ending of the cease-fire did not mean they wanted to pull out of the peace talks, saying it was possible to "talk while fighting."