The ongoing crisis in the Persian Gulf has caused US Secretary of State Rex Tillerson to cancel a planned trip to Mexico in an effort to help end the Saudi-led Coalition of isolation of Qatar. United Arab Emirates foreign minister affirmed the necessity of a Western role in settling the dispute and told the Guardian newspaper that any agreement would need to be overseen by Western allies.

The dispute began because of Qatar’s ties to Iran and Islamist groups, but the ongoing effort to resolve the dispute came to a halt as Qatar awaited a list of demands from the UAE and Saudi Arabia. Tillerson is attempting to broker a deal between the groups, a role he recently was forced and announced through a State Department announcement he would be skipping a meeting of the Organization of American States in Cancun to put his full focus on the Gulf dispute. Tillerson’s goal as mediator is to “de-escalate tension in the Middle East region through in-person meetings and phone conversations…” So far he has made more than a dozen calls and participating in multiple in-person meetings.

Tillerson is believed to be suited to the role because he forged ties with regional leaders while he was working as chief executive officer of Exxon Mobil Corp. President Trump offered the mediation services of Tillerson shortly after the dispute arose. To date, Tillerson has met with top officials from the UAE, Saudi Arabia, and Qatar.

Those involved are expected to submit a list of demand to Tillerson and other mediators in the coming days.