Donald Trump and Joe Biden have both held campaign rallies in the US state of Georgia, as their general election showdown comes into greater focus.
The former president, 77, slammed Thursday’s State of the Union speech as an “angry, dark and hate-filled rant”.
An hour later, President Biden, 81, unveiled new endorsements as he went on the offence against his rival.
Both men are now within striking distance of clinching their respective party nominations for president.
Mr Trump has so far amassed 1,076 delegates and is 139 away from the number needed to lock in the Republican nod. Mr Biden has collected 1,859 delegates, 109 short of what he needs to secure the Democratic ticket.
Each man has the chance to complete the task in primary contests on Tuesday, including in Georgia.
Their shadow-boxing duel on Saturday also comes two days after Mr Biden rebuked his predecessor’s rhetoric and record in harsh terms during his State of the Union address to Congress.
Speaking in the north-western city of Rome, Mr Trump hammered his “grossly incompetent” opponent for “the most divisive, partisan and radical speech ever delivered by a president in that chamber”.
He also zeroed in on border security and the murder last month of Laken Riley, a Georgia college student allegedly killed by an undocumented immigrant.
Immigration is now the top concern for US voters, according to a Gallup poll released last month.
With supporters holding aloft photos of Ms Riley, and her family and friends in attendance, the former president vowed to “demand justice for Laken” and “seal the border”.
He also slammed Mr Biden for rowing back on comments during the State of the Union in which he referred to the suspect as “an illegal”. The president expressed regret in an MSNBC interview that he had not used Democrats’ preferred term – undocumented.
Mr Biden’s controversial remark came during an exchange with top Trump ally Marjorie Taylor Greene, who rallied with Mr Trump on Saturday in Rome, the city she lives in and represents in Congress.
Speaking about an hour’s drive away in the capital city of Atlanta, Mr Biden told supporters: “It can tell you a lot about a person, who he keeps company with.”
He attacked Mr Trump – who also hosted Hungary’s Prime Minister Viktor Orban at his Florida home on Friday – for “sucking up to wannabe dictators and authoritarian thugs all over the world”.
Reframing November’s general election as “a contest between competing forces in a battle for the soul of this nation”, the president reiterated his view that Mr Trump’s “story of resentment, revenge and retribution” was not in the best interests of voters.
Fresh off the buzz of a State of the Union watched on television by more than 32 million Americans, Mr Biden’s campaign for re-election is on the offensive.
He visited the battleground state of Pennsylvania on Friday, and will rally in Michigan and Wisconsin next week, while members of his administration are also fanning out across the country.