During the run-up to the 2012 elections, Kiuchi rejoined the LDP to support Shinzō Abe in his bid for the prime minister's office, remaining a supporter until Abe's resignation in 2020. In the Second Abe Cabinet formed in December 2012, Kiuchi was appointed parliamentary vice-minister for foreign affairs. When the cabinet was reshuffled in September 2014, Kiuchi was promoted to state minister for foreign affairs, a post he retained through the inauguration of the Third Abe Cabinet until October 2015. Between 2015 and 2018, Kiuchi served in the executive of various parliamentary committees and internal LDP commissions, including the Parliamentary Committee on North Korean Abductions and Other Issues, the LDP International Bureau, the LDP Economy, Trade and Industry Division, and the LDP Information Research Bureau. Under the Fourth Abe Cabinet, Kiuchi served as the state minister for the environment from October 2018 until September 2019. In this capacity, he led the ministerial climate talks in Karuizawa, Nagano, as part of the 2019 G20 summit. Since October 2019, he has served as the deputy chairperson of the LDP's Diet Affairs Committee.