The statement is true.
Work Step by Step
After the first ionization process, the nuclear charge of the nucleus stays the same, while there is one electron fewer in the atom. As a result, due to the decrease of electrons, there is less screening to the attraction from the nucleus to the electrons. Therefore, the electrons would experience more attraction from the nucleus and so harder to be removed. The second ionization thus would be more difficult and requires higher energy than the first one. The statement is true.