Several key races in the US general elections, including the Presidential poll are still undecided as ballots continue to be counted.

Toughest challenges before Obama

In the Presidential race, North Carolina, Indiana, and Missouri all show Democrat nominee Barack Obama [Images] and his Republican rival, John McCain [Images] within one percentage point of each other.

All three were previously viewed as critical battleground states for both candidates. However, with Obama leading by 175 electoral votes, the 37 votes no longer hold much sway in determining his presidential bid.

Obama's supporters celebrate his win

Four seats in the Senate have yet to be determined. As per latest reports, Alaska Senator Ted Stevens was just one percentage point ahead of Democrat Mark Begich.

Oregon Senator Gordon Smith had a two point lead on Democrat Jeff Merkley. Minnesota Senator Norm Coleman was neck and neck with Democrat Al Franken and Georgia Senator Saxby Chambliss had a four point lead over democrat Jim Martin.

Excerpts from Barack Obama's victory speech

Although Georgias incumbent leads by four points, state law dictates that in order to win the seat, a candidate must attain over 50 per cent of the vote. If this does not happen, an automatic runoff is held, CNN reported.

With the Democrats currently holding 56 seats in Senate, these four states will determine whether or not the Democrats reach their goal of a filibuster-proof Senate.