Kizza Besigye says he will ask people to take to the streets instead of pressing fraud charges as he did after the 2006 poll.
But Information Minister Kabakumba Matsiko says Uganda is not similar to Egypt.
U.S. Deputy Secretary of State James Steinberg visited Uganda on Friday. He said he planned to meet with President Yoweri Museveni and talk with opposition candidates to find out whether the electoral process is giving them a chance to be heard by voters.
Museveni, who has been Uganda's president since 1986, is widely expected to win the Feb. 18 poll.