Francis plunged headfirst into his agenda upon arrival, denouncing the centuries-long exploitation of Africa by colonial powers, today’s multinational extraction industries and the neighboring countries interfering in Congo’s affairs that has led to a surge in fighting in the east.

The six-day trip, which also includes a stop in South Sudan, was originally scheduled for July, but was postponed because of Francis’ knee problems, which were still so serious on Tuesday that he couldn’t stand to greet journalists in the plane heading to Kinshasa and forced him to use a wheelchair on the ground.

“In addition to armed groups, foreign powers eager for the minerals in our subsoil commit cruel atrocities with the direct and cowardly support of our neighbor Rwanda, making security the first and greatest challenge for the government,” he said.

Francis’ tough words at the start set the tone for the trip, in which the pontiff is aiming to bring a message of peace, a warning to the international community to not look the other way and a recognition that Africa is the future of the Catholic Church.

At the same time, he urged Congolese authorities to work for the common good and not tribal, ethnic or personal interests; and put an end to child labor and invest in education so that “the most precious diamonds” of Congo can shine brightly.

Some women wore colorful dresses and skirts made of pagne, a wax print fabric featuring images of Francis, the Virgin Mary or the Vatican keys, in a celebratory sign of welcome.