UNITED NATIONS (AP) — Colombian President Gustavo Petro’s commitment to transform long-marginalized rural and conflict areas and new peace efforts were the highlights of his first year in office, the U.N. special envoy for the South American country said.

But Carlos Ruiz Massieu condemned the killing of nearly 400 former combatants who signed a 2016 peace agreement and called for “urgent and concrete measures from the authorities for their protection, as well as that of social leaders and human rights defenders.”

He told the U.N. Security Council on Wednesday that lagging progress in implementing rural reforms has limited the transformation in rural and conflict areas that the 2016 peace accord between the government and Colombia’s then-largest rebel group, the Revolutionary Armed Forces of Colombia, or FARC, was expected to bring.

“While a great distance still remains to attain the ambitious goals of the agreement in this respect,” he acknowledged “the increasing government efforts under way to bring about these reforms.”

The 2016 peace agreement ended more than 50 years of war in which over 220,000 people died and nearly 6 million people were displaced. More than 14,000 FARC fighters gave up their weapons under that agreement, but violence between some rebel groups has grown in parts of Colombia.

Colombia’s Foreign Minister Alvaro Leyva told the council that various forms of violence persist and “our efforts and renewed commitment to peace must be maintained and must be our highest task.”

He said it hasn’t been easy and requires perseverance to implement the 2016 agreement, but it must be “inviolable.” He added that Colombia’s decision to ask the Security Council to establish a political mission to verify implementation of the 2016 agreement — which it did in a resolution endorsing the peace deal — “attested to the desire at that time to achieve irreversible reconciliation.”

As the seventh anniversary of the agreement approaches, he said President Petro will in the next few days assume direct responsibility in a unilateral state declaration for fulfilling the commitments in the Security Council resolution.

“I wish to underscore the fact that the dialogues which are currently underway with the various groups and armed actors are a fundamental tool to achieve peace throughout the country, and to alleviate the humanitarian impact of the armed and criminal violence,” Leyva said.

He said the government recognizes that this must go hand in hand with implementing its National Development Plan.

Leyva said the council resolution states that the justice component should apply to all who participated directly or indirectly in the conflict. But the government believes “it should apply to those being investigated or sentenced for the crime of rebellion or other crimes related to the conflict, even if they did not belong to rebellious armed organizations,” he said.

In early August, the Security Council unanimously authorized the U.N. political mission to help verify implementation of a cease-fire agreement between the government and the country’s largest remaining guerrilla group, the National Liberation Army, known as the ELN.

The council also expressed willingness to do the same if a cease-fire is reached with another armed group, the FARC-EMC, which is led by former FARC commanders who refused to join the 2016 peace deal.

U.S. deputy ambassador Robert Wood expressed concern at the ELN central command’s ability to maintain the cease-fire “at a time when various fronts under its command continue to express discontent.”

He cited a recent media report indicating that 40% of ELN members would reject a peace deal with the government “because they continue to see lucrative earnings from drug trafficking and illegal mining.”

Wood called the FARC-EMC’s recent announcement that it would cease offensive operations against the Colombian military and police and begin a 10-month cease-fire “a positive development.”

“But we need to see more progress in this effort before the council considers further expanding the mandate,” he said.

Wood reiterated the U.S. commitment to working with Colombia to implement the 2016 peace agreement.

Achieving its commitments will help bring security and stability, strengthen the protection of human rights, help bring truth and justice to victims of decades of conflict, and enhance economic development and equality in rural and urban areas, the U.S. envoy said.

Britain’s U.N. Ambassador Barbara Woodward also welcomed the government’s recent progress on rural reform and restitution of land to Indigenous communities.

She stressed that full implementation of the 2016 agreement “remains central to peace and reform in Colombia” and echoed U.N. envoy Ruiz’ strong condemnation of violence against ex-FARC fighters, human rights defenders, women leaders and members of the Afro-Colombian communities.