Communist rebel leaders have welcome a possible offer from the Philippines' presumptive president-elect of four cabinet posts.

The party said on Wednesday that an alliance would need to be based on principles such as social justice and national sovereignty, including an end to the presence of US troops.

Rodrigo Duterte, who won the May 9 presidential election by a landslide according to an unofficial count, has said he will probably offer the Communist Party of the Philippines cabinet positions in agrarian reform, environment, social welfare and labour.

"The CPP and the revolutionary forces welcome the possibility of joining presumptive President Duterte in an alliance government, whether in the form of assigning cabinet positions to the CPP or its endorsees or some other more radical form of unity government which the maverick new president might be open to consider," the party said in a statement.

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Al Jazeera's Marga Ortigas, reporting from the capital Manila, said the Communist Party will hand Duterte a list of people it feels are acceptable.

Duterte is also looking into the possibility of releasing all 500 political prisoners, she said.

"This is something Philippine Communists are very happy to see," she said.

American troops have no permanent bases in the country, but hold regular joint exercises and have backed Philippine troops battling Abu Sayyaf fighters in the south.

While Duterte's proposed offer of cabinet posts could foster peace talks, any major political concessions are likely to be complicated, given the many years of fighting and enmity between the rebels and government forces.

Business and industry leaders would also likely oppose demands such as an end to contractualisation, the widespread practice of short-term employment, and higher wages.

The government has also relied on closer military ties with the US amid an increasingly tense territorial dispute with China over areas of the South China Sea.

Source: Al Jazeera and agencies