Long focal lines with transverse spot sizes as small as a few wavelengths are called optical needles. A zeroth order Bessel beam being a good example is widely used in such applications as laser micromachining. In practice Bessel beam generated with an axicon has a peak in axial intensity distribution and is not only due to aberrations caused by planar dielectric material interface. Here, we investigate optical needles with controlled axial intensity distribution via intensity modulation of the incoming beam. We have chosen to generate constant axial intensity Bessel beam and propose spatial transmission mask to do so. Experimental verification is presented using diffractive optics elements based on Pancharatnam-Berry phase. We demonstrate a flattening of the axial intensity profile of the Bessel beam without the alteration to the optical needle diameter.