I would provide new wires rather than extend the existing wires.
I am an advocate for using quality flexible wires and like to use silicone insulated flexible wires
below is a table of the current carrying capability for various gauges.
as the power supply is rated at 24 volts 10 amps,
16 AWG should be adequate for the power cables. because :
A, the ratings displayed, have safety allowances built in, and
B, the 16AWG cable is rated over twice the expected power requirement
don't forget to use the correct terminals for the ends!
I try to make suggestions that I believe to be well founded and safe,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions,
what you do, is YOUR responsibility.