In the message, the bank's outgoing President David Malpass said Saied's tirade had triggered "racially motivated harassment and even violence," and that the institution had postponed a planned meeting with Tunisia until further notice.
"Given the situation, management has decided to pause the Country Partnership Framework and withdraw it from Board review," said Malpass in the note to staff.
AFP understands that ongoing projects will continue and funded projects remain financed.
Hundreds of migrants have flown home from Tunisia, fearful of a wave of violence since the president's remarks.
Last month, Saied ordered officials to take "urgent measures" to tackle irregular migration, claiming without evidence that "a criminal plot" was underway to change Tunisia's demographic makeup.
He claimed that migrants were behind most crime in the North African country, fueling a spate of sackings, evictions and attacks.
"Public commentary that stokes discrimination, aggression, and racist violence is completely unacceptable," said Malpass in the note to World Bank staff.
But he also noted that measures announced by the Tunisian government to protect and support migrants and refugees marked a "positive step," adding that the bank would assess and monitor its impact carefully.
Malpass said that the bank's work in Tunisia is aimed at helping all people, whether they are citizens or immigrants.
The development lender will roll out additional safety measures for its staff on the ground, and may take more action if needed.
The African Union had expressed "deep shock and concern" at Saied's remarks, and governments in sub-Saharan Africa have scrambled to bring home hundreds of frightened nationals who flocked to their embassies for help.
Since the president's speech on February 21, rights groups reported a spike in vigilante violence, including stabbings targeting African migrants.
According to official figures, there are around 21,000 undocumented migrants from other parts of Africa in Tunisia, which is home to around 12 million people.
Many African migrants in the country lost their jobs and homes overnight.
The embassies of Ivory Coast and Mali provided emergency accommodation this week for dozens of their citizens evicted from their homes, including young children.
Citizens of other African countries whose countries have no diplomatic representation in Tunisia have meanwhile set up makeshift camps outside the Tunis offices of the International Organization for Migration.