With 18 days to go before Americans choose their next President, latest polling shows Democratic party candidate Joe Biden inching ahead with an average lead of 4.5 points against US President Donald Trump across six battleground states that account for the lion's share of electoral votes needed to carry the White House.

In nine national-level polls from October 2 till date, Biden leads by a minimum of five points (Rasmussen) and a maximum of 12 points (USC). As the race tightens, FiveThirtyEight, a polling aggregation site, is predicting a 87 per cent chance of a Biden win and a 13 in 100 chance of a Trump win, based on 40,000 simulations of election outcomes.