"With the visit of Secretary of State Tillerson, the relation between Africa and the USA is personified,"Mahamat said, adding that the spat was "a thing of the past".
Tillerson says South Korea is keeping the USA informed about its discussions with North Korea.
On Thursday, during his first trip to Africa, the U.S. diplomat told a news conference in Addis Ababa, Ethiopia, that African leaders need to carefully consider their agreements with China.
He said the aid plan will help people affected by food shortages and conflict in Somalia, South Sudan, Ethiopia and the Lake Chad Basin.
In direct response to Tillerson's comments, Mahamat said African nations were well aware of their priorities and the nature of their foreign partners.
U.S. Secretary of State Rex Tillerson says there are "potentially positive symbols" coming from North Korea but that "we're a long ways from negotiations".
Tillerson, in his speech, warned that China's approach to development in Africa "encourages dependency" that undermines its sovereignty and risks its stability.
Tillerson arrived in Ethiopia, Africa's second most populous nation, on March 7 and visited the African Union headquarters the following day.
"Our country's security and economic prosperity are linked with Africa's like never before", the top US diplomat said before an audience at George Mason University just outside of Washington.
"It's an American model of development that has proven itself to work", he added, continuing that the United States "pursues, develops sustainable growth that bolsters institutions, strengthens rule of law, and builds the capacity of African countries to stand on their own two feet".
Ethiopia is home to some of China's biggest investments in Africa, from a railway to Djibouti that opened past year to factories and industrial parks - as well as the African Union headquarters, which Tillerson visited on Thursday.
"I believe that this incident is of the past", Faki said.
Tillerson did announce Tuesday $533 million in humanitarian aid to help with starvation and conflict-related needs in Ethiopia, Somalia, South Sudan and Nigeria.
Tillerson's African tour, which will also include Djibouti, Kenya, Chad and Nigeria, is taking place after pejorative statements by U.S. President Donald Trump raised indignation among leaders of the continent. It was unclear how many opportunities Tillerson would have to engage substantively with key leaders and African institutions such as the G5 Sahel joint counterterrorism force given the rapid pace and last-minute nature of his trip.