The leaders of Guyana and Venezuela promised in a tense meeting Thursday that neither side would use threats or force against the other, but failed to reach agreement on how to address a bitter dispute over a vast border region rich with oil and minerals that has concerned many in the region.

Instead, a joint commission composed of the foreign ministers of both countries and other officials will address the problem, with a report expected within three months.

Guyanese President Irfaan Ali and Venezuelan President Nicolás Maduro agreed to meet again in Brazil within three months or at another agreed-upon time, according to an 11-point declaration read at a press briefing late Thursday at which no questions were allowed.