Sept 27 (Reuters) - U.S. President Joe Biden"s national security adviser Jake Sullivan will travel to Saudi Arabia and the United Arab Emirates along with the U.S. special envoy to Yemen, the White House National Security Council said on Monday. Brett McGurk, the NSC"s Middle East and North Africa Coordinator, will also join Sullivan and Tim Lenderking, the council spokeswoman Emily Horne said in a statement, adding that Sullivan will meet "with senior leaders on a range of regional and global challenges." Sullivan will depart on Monday and hold discussions with Crown Prince Mohammed bin Salman about Yemen, according to the Associated Press, which first reported the trip. He is also expected to meet deputy defence minister Khalid bin Salman, a brother to the crown prince, it said, cited unnamed sources. The United Nations has described the situation in war-torn Yemen as the world"s largest humanitarian crisis. Seven years of fighting have also plunged the nation into an economic crisis, triggering food shortages. The United States and Saudi Arabia, which leads a military coalition fighting Yemen"s Iran-aligned Houthi group in Yemen"s conflict, have pledged millions more dollars in additional aid, as have other countries. https://reut.rs/2WewHkn Biden has taken a tougher stance with Saudi Arabia than his predecessor Donald Trump, criticizing the kingdom over its human rights record while releasing a U.S. intelligence report earlier this year implicating the Saudi crown prince in the 2018 killing of Saudi dissident journalist Jamal Khashoggi. The prince denies any involvement. read more Earlier this month, the FBI released a newly declassified document about its investigation of the Sept. 11, 2001, attacks on the United States and allegations of Saudi government support for the hijackers, following an executive order by Biden. The Kingdom has long said it had no role in the attacks.