A former Republican senator from New Hampshire says Nikki Haley should visit the early-primary state as soon as possible to explore a 2020 challenge against President Trump.

“After four years of Donald Trump, America will want a president of sound mind and dignified presidential bearing," former Sen. Gordon Humphrey told the Washington Examiner.

Haley announced her resignation as U.S. ambassador to the United Nations on Tuesday. She opposed Trump in 2016, contributing to suspicion about her departure, which will take effect later this year.

The two-term former senator expressed interest in a Haley candidacy after she told reporters in the Oval Office that she would not challenge Trump in 2020.

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"Ambassador Haley should come to New Hampshire the day she leaves the U. N. I’ll gladly pick her up at the airport,” Humphrey said.

In televised remarks Tuesday, Haley sat beside Trump and said she would not challenge him.

"For all of you that are going to ask about 2020, no, I am not running for 2020," the former South Carolina governor said. "I can promise you what I'll be doing is campaigning for this one. I look forward to supporting the president in the next election."

Humphrey left office in 1991 after two six-year terms in the Senate. He served one term in the New Hampshire senate and remained active in state politics, endorsing Ohio Gov. John Kasich in the 2016 primary.