WASHINGTON—Negotiations over the withdrawal of existing digital services taxes after a landmark corporate tax deal should ultimately end the threat of tariff wars between the United States and several countries over the levies, U.S. Treasury officials said. In the OECD tax agreement, 136 countries last Friday agreed to adopt a 15 percent minimum corporate tax and partly reallocate taxing rights for large, highly profitable companies to countries where they sell products and services. In return, the deal requires all countries to remove unilateral digital services taxes (DST) that largely targeted U.S. technology giants. It also prohibits new digital levies immediately until the agreement enters into force at the end of 2023. Transitional arrangements for removing DSTs “are being discussed expeditiously.” The Treasury officials told reporters on a conference call that talks over the details of these arrangements were expected to obviate the need for the United States to pursue retaliatory …