The race between Kamala Harris and Donald Trump has tightened in two of the Northern battlegrounds, New York Times/Siena College polls found.

Democratic presidential candidate Kamala Harris and her Republican rival Donald Trump are in a tight race in the key states of Michigan and Wisconsin, according to an opinion poll by the New York Times and Siena College released on Saturday.

New polls show the presidential candidates neck and neck in key battleground states that could determine the course of the race.

While Harris has a slight lead nationally, there's no clear leader in the seven swing states likely to decide the election.