Washington | The electoral battle between Vice President Kamala Harris and former president Donald Trump appears to have gone to the wire, according to latest opinion polls.

Harris, 60, is the nominee of the Democratic Party and Trump, 78, is the Republican nominee. Their party members and support bases are united with their respective parties, and independent votes might decide who would be the next occupant of the White House.

To win the elections, a candidates needs 270 of the electoral college votes. Latest opinion polls indicate that the elections will be decided by the results in seven battle ground states of Arizona, Nevada, Wisconsin, Michigan, Pennsylvania, North Carolina and Georgia.

Of these, Michigan and Pennsylvania play key role to them reaching the 270-mark.

The presidential race appears to be hurtling toward a photo finish, with the final set of polls by The New York Times and Siena College finding Harris gaining new strength in North Carolina and Georgia even as Trump erases her lead in Pennsylvania and maintains his advantage in Arizona, the daily reported Sunday.

According to The New York Times, Harris is now narrowly ahead in Nevada, North Carolina and Wisconsin, the polls show, while Trump leads in Arizona.

"The polls show them locked in close races in Michigan, Georgia and Pennsylvania. But the results in all seven states are within the margin of sampling error, meaning neither candidate has a definitive lead in any of them," the daily reported.

The Real Clear Politics, which tracks all the major national and battleground polls, said it's a tie between Trump and Harris. In the national polls, Trump leads by 0.1 percentage points, and in battleground states the former president has an edge of 0.9 percentage points.

In the battleground states, as per Real Clear Politics, Trump has a lead, though within the margin of error, in Georgia, North Carolina, Pennsylvania and Arizona; while Harris has an edge in Michigan and Wisconsin.

"The presidential race is tight, and neither candidate has a clear lead," The Hill said.

In its final poll, the NBC News said the poll shows Harris getting support from 49 per cent of registered voters in a head-to-head matchup, while Trump gets an identical 49 per cent. "Just two percent of voters say they're unsure about the choice," the news channel said.