The United States and Qatar have signed an agreement aimed at shoring up the Gulf nation's counterterrorism efforts.

The memorandum of understanding was signed Tuesday during a visit to the energy-rich country by U.S. Secretary of State Rex Tillerson.

He is in the Gulf on a mission aimed at ending a rift between Qatar and four Arab states that accuse it of supporting extremists. Qatar denies the allegation.

Senior Tillerson adviser R.C. Hammond says the deal outlines "future efforts Qatar can take to fortify its fight against terrorism and actively address terrorism funding issues."