The US State Department says the elections can be salvaged and the announced decisions by the opposition groups to pull out from the polls are not necessarily final.
State Department Spokesman P.J. Crowley told journalists that the US goal is to produce as competitive an election as possible, VOA News reported.
He added that the current elections environment is difficult and there are complex issues to solve.
Mr. Crowley said the presidential election is a major step toward the 2011 referendum on the future of southern Sudan, and getting it right will be a big advance for both the north and south.
A senior State Department official who spoke to reporters said a boycott would not be in the long-term interests of opposition parties.
Meanwhile, US special envoy for the Sudan, is in Khartoum meeting the different parties in a bid to rescue the elections.