Ukrainian President Petro Poroshenko has appointed U.S. Republican Senator John McCain as an adviser.
Ukraine's pro-Western authorities are putting together an advisory council to help conduct reforms and build global support for Ukraine.
A decree released by the Ukrainian presidency on May 14 says that pending his agreement, McCain will become a member of the council, along with former Swedish Prime Minister Carl Bildt.
The Advisory International Council of Reforms is to be headed by Mikheil Saakashvili, the fiercely pro-Western former president of Georgia, and will also include Elmar Brok, a member of the European Parliament, and economist Anders Aslund.
McCain, who is a former presidential candidate, tweeted that he would be honored to take up the post, but added that he first had to be cleared by the Senate.
Kyiv is fighting a pro-Russian rebellion in eastern Ukraine that has killed more than 6,000 people since April last year.
Sporadic violence continues despite a shaky cease-fire sealed in February.