Stefanishyna will be the ambassador to the United States. A source in the OP explained why not Umerov

President Volodymyr Zelenskyy nominated by the acting Vice Prime Minister for European and Euro-Atlantic Integration Olha Stefanishina and appointed her his special envoy for the transition period. The relevant decree published on the President's website. The interlocutor LIGA.net in the President's Office explained that another candidate for the position in Washington, Rustem Umerov, for the time being, he will be engaged in negotiations without reference to a specific capital.

According to Zelenskyy, in her new role as special envoy, Stefanishyna will work to "keep up the pace in relations with America" while the procedures for approving her candidacy for the ambassadorship continue.

"In a few years, we have come closer to the European Union than in the previous few decades. Olha also participated in negotiations with the United States on a new format of our economic cooperation and the creation of Ukrainian-American Recovery Investment Fund. We will continue to work with the United States on this basis, adding mutually beneficial economic content to our political and diplomatic cooperation," the head of state said.

Earlier, the interlocutor LIGA.net in the Presidential Office confirmed that Stefanishyna would be the new ambassador to the United States and noted that the authorities had decided that another candidate, Umerov, "would be better off negotiating without being tied to any capital."

"Because over there [in the US], he might have to sit in Congress for days, and we have another Istanbul or something [like that]. Now he has just started some more contacts with his arms partners, so he is back in this [process]," the source said.

According to him, Stefanishyna was previously on the list of candidates for ambassador to the United States, and the former prime minister was also considered for the post Denis Shmyhal – "depending on the tasks that the president would define."

However, the source explained, the authorities later decided that it would be better to appoint Shmyhal the head of the Ministry of Defense as he "knows the system very well, and this kind of prime ministerial experience will be useful there."

• on July 16, the Specialized Anti-Corruption Prosecutor's Office opened criminal proceedings following a journalistic investigation into Stefanishyna. So far, no one has been notified of suspicion, pre-trial investigation is ongoing.
• Earlier, Ukrayinska Pravda published investigation that people from Stefanishyna's inner circle, including her ex-husband, received four large real estate properties through ARMA. These properties include Trade union building on Independence Square.
• In 2020, Stefanishyna confirmed that she was a suspect in the case of the fugitive Lukash, the head of the Yanukovych-era Justice Ministry. The official denied her guilt.