All noncommissioned officers and petty officers of the organized militia shall be appointed at the discretion of the appointing officer
upon the nomination of the officer under whose immediate command they are to serve. The appointment shall be in accordance with regulations of the United States and regulations issued pursuant to this chapter. Appointing officers shall be designated in regulations issued pursuant to this chapter. The appointment of a noncommissioned officer or a petty officer may be terminated as prescribed by regulations issued pursuant to this chapter.