Here's what it says in its 2017 Annual Report Income Tax Footnote:
"Prior to enactment of the TCJA, with few exceptions, U.S. income taxes had not been provided on undistributed earnings of UTC's international subsidiaries as the Company had intended to reinvest such earnings permanently outside the U.S. or to repatriate such earnings only when it was tax effective to do so. As of December 31, 2017 such undistributed earnings were approximately $34 billion. The Company is evaluating the impact of the TCJA on its existing accounting position related to the undistributed earnings. Due to the inherent complexities in determining any incremental U.S. Federal and State taxes and the non-U.S. taxes that may be due if the earnings were remitted to the U.S. and in accordance with SAB 118 this evaluation has not been completed and no provisional amount has been recorded in regard to this amount."
Also, United Technologies elected not to disclose the amounts of the components of its 2017 Total Income Tax Expense due to the US Trump Tax Cuts Act.