UNITED NATIONS -- Secretary-General Antonio Guterres is urging the UN Security Council to consider imposing sanctions on key players in Mali who are obstructing implementation of a 2015 peace agreement if there are no immediate results on the ground.

The new UN chief said in a report to the council circulated Monday that progress in implementing the peace deal between the government and rebel groups remains too slow.

"The peace process in Mali is at a critical juncture," he said. "Notwithstanding some progress made over the past 18 months ... the signatory parties continue to disagree on key interim measures, thus stalling the process for all other provisions."

Guterres said that amid renewed fighting between a government-allied militia known as the Platform and a coalition of groups seeking autonomy in northern Mali that includes ethnic Arabs and Tuaregs, key provisions of the agreement have not been put in place. He cited the failure to establish interim authorities and mixed patrols as well as the postponement of a national reconciliation conference scheduled for December.

The Tuareg rebellion in Mali's far north has been a source of conflict for decades with the government.

A 2012 uprising was blamed for prompting mutinous soldiers to overthrow Mali's president of a decade, creating a power vacuum that ultimately led to an Islamic insurgency and a French-led war that ousted the jihadists from power in 2013. But Jihadists remain active in the region more than three years later, frequently attacking Malian and French soldiers as well as UN peacekeepers trying to stabilize the north.

Guterres urged all parties to immediately stop fighting and resume "a constructive dialogue," noting that only six months are left in the interim period stipulated in the peace agreement.

He also urged the international community, including a team of mediators, to redouble efforts and use their "full political weight" to ensure action by the signatories.

If international efforts and dialogue fail "to achieve immediate results on the ground, I call on the Security Council to consider, in the coming months, the imposition of targeted sanctions against those who obstruct implementation of the peace agreement," Guterres said.

The secretary-general warned that "the limited progress in putting in place the security arrangements foreseen in the agreement has facilitated the spread of insecurity from the far north to the center of Mali, with terrorist and violent extremist groups expanding their activities and consolidating their presence."

He said growing insecurity in border areas between Mali and Burkina Faso and Niger, together with the impact of drug trafficking on peace efforts, demonstrates the need for regional cooperation to tackle security threats.

Guterres urged the government to redouble its efforts to redeploy Malian forces in the north and center of the country where security remains volatile.