Former US vice president Mike Pence and former New Jersey governor Chris Christie are expected to join the Republican field for the 2024 US presidential election next week, outlets reported on Wednesday.
Mr Pence, who served under Donald Trump, is planning to launch his presidential campaign at a rally in the battleground state of Iowa, NBC News and the Des Moines Register reported.
He will announce his run at the June 7 event in Des Moines, along with a campaign video.
Mr Pence will have a challenge in separating himself from Mr Trump, who had an outsized presence nationally during their work together.
Mr Trump is also leading the campaign field, with Florida Governor Ron DeSantis in second place.
Mr Trump has criticised Mr Pence for not defending him in the violent pro-Trump insurrection at the US Capitol on January 6, 2021.
The former president wanted him to challenge the Congressional certification of the 2002 election for Joe Biden. Because of this, Mr Pence may fail to win votes from Trump supporters.
Before serving under Mr Trump, he was a governor of Indiana and a US representative in the House.
Mr Christie is expected to make his presidential bid announcement during a town hall event at Saint Anselm College in New Hampshire on June 6, Axios reported.
Once a prominent supporter of Mr Trump, he has since become one of his harshest critics after the January 6 Capitol attack.
Mr Christie rose to prominence in 2012 after Hurricane Sandy ravaged the New Jersey coast and he made the controversial decision to tour the damage with Barack Obama, who was president at the time.
While governor, Mr Christie also travelled to Israel where he met Prime Minister Benjamin Netanyahu and then president Shimon Peres. He also visited Jordan as a guest of King Abdullah II.
His campaign is expected to portray the US in a more hopeful light, Axios reported. He is also expected to use his brash personality to continue criticising Mr Trump.
The former president holds a commanding lead over his Republican rivals.
Mr Trump has more than 54 per cent of support among likely Republican voters, FiveThirtyEight's polling aggregator shows. His closest rival, Mr DeSantis, is at 20.4 per cent.
Mr Christie and Mr Pence would join a crowded field that also includes former UN ambassador Nikki Haley.
Mr Christie ran for president in 2016. It would be Mr Pence's first bid.