A U.N. helicopter aiding humanitarian efforts was hit by gunfire on Thursday while flying over Port-au-Prince, later landing safely, the WFP said.
The spread of violence from land and sea, she said, is "spreading terror and fear, overwhelming the national security apparatus."
More than 4,200 people have fled their homes in fresh attacks around the capital since last Thursday, according to U.N. estimates,
In Haiti, Kenyan officers have conducted raids that resulted in the deaths of over 20 gang members within the past week.
According to previous UN reports, weapons trafficked into Haiti primarily originate from the US, particularly Florida, with additional arms flowing through intermediaries in the Dominican Republic and Jamaica.
Kanja announced that up to 600 police officers are currently undergoing training and will be deployed to lawless-hit Haiti next month.
Visit by the Haitian leader is meant to drum up support for the release of funds and the deployment of the remaining troops.
Near-famine conditions push boys to pick up guns while girls are sexually abused and forced into domestic work in the Carribean nation.
Outgoing President Leblanc Fils opposed the move citing unresolved corruption accusations against three other councillors who remain voting members and signed off on the transition.
Haiti is reeling after members of the Gran Grif gang stormed through the town of Pont-Sonde in the western Artibonite region early on Thursday, killing at least 70 people, including infants, and forcing over 6,000 residents to flee.
The Gran Grif gang is based in the area and has been accused of mass kidnappings, rapes, murders, hijackings and forcing farmers off their lands, as well as child recruitment.
Five high-profile individuals with corruption on Wednesday, including three members of an interim governing council, over a scandal involving bribing the chairman of a state-owned bank.
This decision follows President William Ruto's recent visit to Haiti, where he assessed the Kenyan police mission.
Gang violence has displaced more than 700,000 people in Haiti, according to UN estimates.
Haiti has been plagued by violence and insecurity at the hands of armed gangs, amid ongoing political, socioeconomic and humanitarian challenges.
Kenya had initially pledged to send 1,000 officers, and Ruto confirmed that the remaining personnel would be deployed in January 2024 to reach the full target.
He emphasised that the mission, which has led to significant improvements in Haiti, must continue to receive the necessary backing to sustain its progress.
Ruto acknowledged that Kenya's decision to send forces to Haiti had raised questions, but defended it as a commitment to international peace and security.
The 15-member UN Security Council is due to vote on September 30 on the mandate renewal.
