The East African country's population grew from 44.9 million in 2012 to more than 60 million, according to the census carried out earlier this year, with President Hassan saying the numbers reflected an annual increase of 3.2 percent.
"Such population might not be a big deal for a huge country like ours but it's a burden when it comes to allocating resources and delivering social services," Hassan said during an event broadcast live from the capital Dodoma.
"We need development strategies to serve these people," she said.
Tanzania's commercial capital Dar es Salaam is poised to become one of the world's most heavily populated cities in the years to come.
The Indian Ocean port remains the most populated region with around 5.4 million residents, while the semi-autonomous archipelago of Zanzibar is home to 1.9 million people, an increase of 600,000.
A World Bank report in 2019 said Dar es Salaam was "one of the fastest growing cities in Africa, and with a growth rate of 6.5 percent, it is expected to reach 10 million residents by 2030.
"Because of this rapid growth, the city faces serious congestion and mobility challenges, which are worsened by an undeveloped road network."
"We need to start preparing development projects for these people and make necessary reforms in our policies to match with the current numbers," Hassan said, pointing out that the country's population was projected to reach 151.2 million in 2050.