Some 13,000 UN peacekeepers are in Liberia
The UN Secretary General, Ban Ki-Moon, has warned that the burgeoning drugs trade in Liberia is a serious threat to the country's long-term stability.
Mr Ban said independent security institutions needed to be implemented in order to deal with the problem.
He added that drug gangs continued to affect peace in neighbouring Sierra Leone and Ivory Coast.
If left unchecked the situation could spark renewed conflict in the West African region, Mr Ban said.
In recent years West Africa has become a key transit point for drugs en route from the Americas to Europe.
In a report to the UN Security Council, Mr Ban said Liberia continued to make significant progress in consolidating peace after more than a decade of civil war - but that those gains remained fragile.
The report on the work of UN peacekeepers in Liberia saw Mr Ban express concerns over the state of rule of law, security and job creation.
Some 13,000 peacekeepers are in the country monitoring the implementation of a 2003 peace deal that ended the civil war in which more than 250,000 people died.
Mr Ban cited the prevalence of rape, armed robbery, mob violence and ethnic tensions as of particular concern.
"It is critically important that... Liberia make every effort to develop national security institutions that are independently operational," he said.
He noted that Liberia continued to be affected by a number of potentially adverse developments such as the drugs trade and from various armed groups.
In reference to a claim made by the ruling military authority in Guinea, Mr Ban said: "The presence of armed Liberian combatants with uncertain intentions in neighbouring countries... remains a serious cause for concern."