The two-person race for the US Republican presidential nomination is intensifying. Both candidates are competing in New Hampshire, which is set to vote Tuesday in the latest state-by-state primary election.

Former President Donald Trump faces ex-United Nations Ambassador Nikki Haley in a poll that is open both to members of the Republican Party and undeclared voters.

The contest was reduced to Trump versus Haley after Florida Governor Ron DeSantis quit his campaign on Sunday.

The two remaining candidates held rallies in New Hampshire on the eve of the state's primary.

Trump addressed the crowd and referred to a general election in which he would face sitting President Joe Biden. He said, "Tomorrow we're going to win New Hampshire, and then we're going to defeat crooked Joe Biden and we are going to make America great again."

Haley targeted her primary opponent, saying that chaos follows Trump. She also said, "We can't be a country in disarray and have a world on fire and go through four more years of chaos, because we won't survive it."

The political analysis website RealClearPolitics shows that as of Monday, Trump's average approval rating in New Hampshire opinion polls stood at 54.9 percent. Haley's was 36.7 percent.

After Trump's outright victory in the Iowa caucuses, Haley needs to win the New Hampshire primary or come in a very close second.

Some observers say that failure to do either could make it difficult for Haley to continue her campaign, adding that they believe that Trump will secure the party's nomination.