UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 American Assets Trust, Inc. ☒ Yes ☐ No American Assets Trust, L.P. ☐ Yes ☒ No FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2019 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to AMERICAN ASSETS TRUST, INC. (Exact Name of Registrant as Specified in its Charter) Commission ...