Donald Trump is reportedly scaling back his election campaign in three states he was tipped to win just weeks ago.

As polls shift in the US presidential race and Trump’s path to the White House appears to narrow, there were reports on Thursday (US time) that the Republican campaign was putting less emphasis on New Hampshire, Minnesota and Virginia.

It marks a dramatic shift since the end of the Republican National Convention in July, when Trump appeared to have the momentum to win November’s election.

In the weeks after, his campaign held rallies in Virginia, Minnesota (home of Harris running mate Tim Walz and firmly Democrat as far back as 1972), and New Jersey, a state most recently won by a Republican in 1988.

In memos, campaign staff wrote that both states were “in play.”

But, according to Thursday’s report in Axios, the entry of Kamala Harris as the Democratic candidate has forced such a shift that Republicans are now focusing resources on the so-called “blue wall” states – Pennsylvania, Michigan and Wisconsin. All are crucial to victory for both candidates.

Pennsylvania, where the latest CNN poll shows Trump and Harris tied at 47 per cent each, is seen as particularly critical.

Franklin & Marshall College Poll director Berwood Yost said “obviously Pennsylvania’s the biggest prize.”

“I think it’s the one state Harris really needs to have to make her path to the presidency viable,” he said.

“It’s certainly shaping up to be really close right now. Before Biden dropped out, it was clearly the state that was moving away from Democrats and she certainly righted the ship.”

Harris will be there again on Friday, for her 10th visit this year.

Axios said Republicans were also putting more effort into North Carolina, Arizona and Nevada. Polls had Trump significantly ahead in all three states until Harris’s election entry whittled away his lead.

“In North Carolina, for example, the campaign and MAGA Inc … have spent more than $US16 million ($24 million) on ads — a sign they’re taking Harris’ prospects there seriously,” Axios said.

By contrast, Harris has focused on Michigan, Wisconsin and Pennsylvania since President Joe Biden dropped his re-election bid and endorsed his Vice-President for the election. Those states have been the centrepiece of successful Democratic campaigns.

She has also frequently visited Arizona, Nevada and Georgia, all won narrowly by Biden in 2020, and North Carolina, which she hopes to nab from Trump.

On Wednesday, Harris was in New Hampshire to talk up a package of tax incentives for small business.

The state has not voted for a Republican since George Bush in 2020. But, across the border is Maine, which splits its electoral votes, allowing candidates to win some without carrying the full state.

It follows reports in The Boston Globe earlier this week that a Trump volunteer had sent an email stating the campaign “has determined that New Hampshire is no longer a battleground state”.

The email reportedly urged Trump to focus instead on Pennsylvania. The comments were rejected by the Republican campaign.

“We have new staff, offices, and volunteers weekly – with more enthusiasm, energy, and support from people and states Democrats take for granted,” Trump campaign battleground states director Rachel Reisner told Axios.

The campaign also argues it can still win in Virginia, despite recent polls showing Harris building a consistent lead.

“It’s a dead heat right now. I mean dead heat,” Eric Trump said last month.

“I think there’s a very good chance my father wins Virginia. I truly believe that we’re going to win the state.”