UN secretary-general Antonio Guterres wants Venezuela and Guyana to refrain from "aggravating" their ongoing border dispute and allow the International Court of Justice (ICJ) to do its job.
The issue of which country rightfully owns the Essequibo region is before the ICJ, but on November 14, the court will hear Guyana's request for provisional measures to be taken against Venezuela.
Venezuela plans to host a referendum on December 3 to decide whether it will annex two-thirds of Guyana. The Guyanese government recently asked the court to help prevent this.
In a statement on Thursday, Guterres' spokesman Stéphane Dujarric said Guterres is following the issue with concern.
"He trusts that both parties will demonstrate good faith and avoid any action that would aggravate or extend the controversy.
"In January 2018, after carefully analysing developments in the good offices process that had taken place over the preceding years, the secretary-general, in the exercise of the power and responsibility conferred on him by the 1966 Geneva Agreement, chose the ICJ as the means that was next to be used for the solution of the border controversy between the two countries."
The statement added, "(Guterres) does not express a view on matters that are the subject of ongoing judicial proceedings."