The Church's 1986 declaration on liberation theology "carefully assesses what can be seen as positive [about it] in the Catholic sense", Archbishop Müller told the Kathpress news agency.
Liberation theology was about a concrete commitment to the poor but it must not be based on a Marxist or atheist concept, he said.
"We must show up unjust structures and actively combat them as they diametrically contradict the Christian image of humanity. No one may be excluded from the goods of the world and that goes for the relationship between peoples."
With a thinly veiled reference to relations between the US and South America, he went on: "We cannot accept that some countries regard a whole half continent as their backyard."