US Secretary of State Rex Tillerson will hold talks with President Kenyatta later this week but is not expected to meet with Raila Odinga, the State Department's top Africa official said on Monday.
Donald Yamamoto, the acting assistant secretary of state for African affairs, noted in a press briefing that he and US Ambassador Robert Godec have spoken with Mr Odinga and other Nasa figures on numerous occasions.
Mr Yamamoto also referred to "behind-the-scenes" contacts taking place between US officials and leaders of the opposition in Kenya. These contribute to "robust relationships" with Mr Odinga and others in Nasa, he said.
"We're not ignoring the opposition," the acting head of the Africa Bureau added. "It plays a critical role".
But "the main focus is to talk to the government," Mr Yamamoto said in regard to Secretary Tillerson's week-long visit to Kenya and four other African countries that commences on Tuesday.
Mr Yamamoto also firmly endorsed the performance of Ambassador Godec, whom the opposition has accused of siding with President Kenyatta in disputes over the validity of recent elections.
Some Nasa members of Parliament have called for Ambassador Godec to be recalled from Kenya.
Mr Yamamoto noted that Washington's envoy to Nairobi is among the most senior US diplomats serving in Africa. He said Ambassador Godec stands as "a model of leadership and engagement."