Harris began her African tour on Sunday in Ghana before flying late on Wednesday to Tanzania's commercial capital Dar es Salaam, where she is due to hold talks with President Samia Suluhu Hassan later on Thursday.

Her office announced plans to improve trade and other aspects of bilateral relations, including a memorandum of understanding (MOU) between the Export-Import Bank of the United States (EXIM) and the government of Tanzania.

This will facilitate up to $500 million in U.S. export financing to Tanzania to support exports of goods and services in sectors including infrastructure, transportation, digital technology, climate and energy security and power generation.

Harris's office also highlighted U.S. support for a plan by LifeZone Metals to open a new processing plant in Tanzania.

The facility will use low-emission technology to process nickel and other minerals mined in the East African country, with a view to start delivering battery grade nickel to the United States from 2026, Harris's office said.

She is due to stay in Tanzania until Friday, when she will depart for Zambia, the final stop on her tour.

Her visit to Dar es Salaam marks a return to international engagement by Tanzania under President Hassan, after a period of isolationism under her predecessor John Magufuli, who cancelled all his ministers' foreign trips and discouraged travel.

Hassan has won praise internationally for restoring political rights suspended by Magufuli, who died in office in 2021.

He had banned political rallies by anyone other than elected officials, cracked down on Tanzania's LGBT community and arrested scores of opposition supporters.

He had also rejected COVID-19 vaccines and urged Tanzanians to put faith in prayer and remedies such as steam inhalation.

Hassan reversed the policies upon coming to power with a COVID-19 vaccination drive and earlier this month, Tanzania passed the milestone of fully vaccinating 50% of its population.

But human rights groups say violations continue, including government targeting of online media outlets. Hassan's education minister also banned a series of children's books from schools last month for allegedly promoting homosexuality.

(Reporting by Nuzulack Dausen in Dar es Salaam and Aaron Ross in Nairobi; Writing by Estelle Shirbon; Editing by Alexander Smith)