DUBAI - The United States and Qatar signed an agreement on combating terrorism and its financing during a visit to Doha by US Secretary of State Rex Tillerson, his senior adviser R.C. Hammond told reporters. 'Qatar and the United States have signed a memorandum of understanding between the two counties outlining future efforts Qatar can take to fortify its fight against terrorism and actively address terrorism funding issues,' he said. 'This is a hopeful step forward,' Hammond added.