Yemen’s Prime Minister Maeen Abdulmalik Saeed left the interim capital Aden on Wednesday morning for Riyadh amid stalled implementation of the the Saudi-brokered Riyadh Agreement, according to government officials, who didn’t provide details about the reasons for his departure.   

The agreement, which outlines a series of political, economic, and security arrangements to foster sustainable governance in Yemen’s south, was signed on Nov. 5 between the secessionist Southern Transitional Council (STC) and Yemen’s internationally recognized government.

An official in the PM’s office said Saeed’s departure was related to the failure to implement the Riyadh Agreement.

Yemeni army commanders were recently in Riyadh for a week to discuss a way forward amid roadblocks to the implementation of the agreement’s military annex.