Donald Trump's campaign plans to treat Nikki Haley as irrelevant after he won the Republican primary in her home state of South Carolina on Saturday, skipping attacks on her to focus instead on a rematch with Democratic President Joe Biden, advisers said.

The former president has easily swept all five Republican nominating contests thus far, winning states in the Midwest, Northeast, South and West and knocking out every challenger save Haley, a former South Carolina governor, along the way.

Saturday's win in South Carolina makes Trump's march toward the Republican presidential nomination appear inevitable, and leaves Haley, despite her vow to battle on, no clear path to beating him.