US President Donald Trump has picked state department spokeswoman Heather Nauert to be America's new UN ambassador.
The president also nominated William Barr as the new attorney general.
Ms Nauert, a former Fox News presenter, was made state department spokeswoman in April 2017, her first government position.
Her predecessor at the UN, Nikki Haley, announced in October that she would leave the post by the end of the year.
Ms Nauert's appointment to the UN role now has to be approved by the US Senate.
After making the announcement, President Trump told reporters: "She's very talented, very smart, very quick, and I think she's going to be respected by all."
Who is Heather Nauert?
In addition to her state department role, the 48-year-old was also appointed acting undersecretary for public diplomacy and public affairs in March this year.
She worked for Fox News from 1998 to 2005 and, after two years away during which she worked for ABC, she returned to Fox in 2007, later becoming a presenter for Fox & Friends.
Fox News has been a consistent supporter of the president and he often cites its programmes.
Ms Nauert made headlines in June when, speaking in her state department role, she cited the World War Two Normandy landings in relation to America's "strong history" with Germany.
The skills to sell 'America first'
By Nada Tawfik, BBC UN reporter
Heather Nauert's meteoric rise is remarkably unusual considering that she has been in government for less than two years, and has never specialised in international relations.
Past ambassadors have been scholars, diplomats or prominent politicians. The role has often gone to skilled negotiators and leading names in US foreign policy, such as Adlai Stevenson and Madeleine Albright.
But President Trump values her loyalty and her TV skills. He trusts her to effectively sell America First over multilateralism. Diplomats at the UN will know she is held in high regard by the president, his daughter and Secretary of State Mike Pompeo.
They will also be aware of how her resume sharply contrasts with theirs. It will be interesting to see how those dynamics could play out during this tumultuous time on the Security Council, with the most challenging crises being Yemen, North Korea and Syria.
Who does she replace?
Ms Haley has served for nearly two years as UN ambassador.
The 46-year-old former South Carolina governor - one of the few women in the Trump cabinet - gave no reason for leaving, but dismissed speculation she was planning to run for president in 2020.
President Trump said she had done "an incredible job".
Former deputy National Security Council adviser Dina Powell and Mr Trump's daughter Ivanka were names initially floated as possible replacements for Ms Haley.
Will it be a cabinet position?
US media has suggested the role will be sub-cabinet level, as it was under the past two Republican administrations.
The Democratic Clinton and Obama administrations elevated it, and this status has been retained under President Trump.
In 2008, John Bolton, a former UN ambassador and the current national security adviser, said the role did not merit cabinet rank.
"One, it overstates the role and importance the UN should have in US foreign policy, second, you shouldn't have two secretaries in the same department," he said, according to the New York Times.