In the government of Prime Minister Yahya Ould Ahmed El Waghef, named on May 11, 2008, Khouna was appointed as Minister of Foreign Affairs. The inclusion of Khouna and others who had served under Taya in Waghef's government was controversial, however. This government survived for only two months, and Khouna was not included in the next government, appointed on July 15, 2008. In any case, the coup of August 6, 2008 led to the toppling of President Sidi Mohamed Ould Cheikh Abdallahi and his government.