Treaty signed at Kiev July 22, 1998; Transmitted by the President of the United States of America to the Senate November 10, 1999 (Treaty Doc. 106-16, 106th Congress, 1st Session); Reported favorably by the Senate Committee on Foreign Relations September 27, 2000 (Senate Executive Report No. 106-24, 106th Congress, 2d Session); Advice and consent to ratification by the Senate October 18, 2000; Ratified by the President January 5, 2001; Ratified by Ukraine February 10, 2000; Ratifications exchanged February 27, 2001; Entered into force February 27, 2001. With annex.
It was one of the last things Bill Clinton signed off on before leaving office.
Sure there is. It's over 20 years old now.
Link to the PDF
Are you sure it is in effect? This page says there isn't such a treaty: https://ua.usembassy.gov/u-s-citizen-services/arrest-of-a-u-s-citizen/information-u-s-citizens-arrested-ukraine/
https://www.state.gov/12978
It was one of the last things Bill Clinton signed off on before leaving office.
Here's a bonus article just because.
https://arizonadailyindependent.com/2019/09/29/treaty-with-ukraine-on-mutual-legal-assistance-in-criminal-matters/