Since you provided no context at all, I hesitate to even try to construct a phrase corresponding to "no remorse." I can, however, address the individual term "remorse."

The American Heritage Dictionary defines "remorse" as, "moral anguish arising from repentance for past misdeeds; bitter regret." As such, it is not an exact synonym for "regret," which is defined by the same authority as, "a feeling of disappointment or distress about something that one wishes could be different."

Although the two terms are close, "remorse" is usually translated as NADAM, while "regret" is translated as ASAF.

The phrase "no remorse" would be translated according to how it fits in its sentence.

Fuad

In addition to Fuad's suggestion for the word "remorse", another term could be used: "تأنيب ضمير" ta'neeb Dhameer, twinge of conscience.

Regards

The transliterations would be:
la nadam
la tanaddum
la ta'neeb dameer
la wakhz dameer

All of the above gives the meaning of: no remorse.

HTH

Mona

The transliterations would be:
la nadam
la tanaddum
la ta'neeb dameer
la wakhz dameer

Each of the above gives the meaning of: no remorse.

HTH

Mona

in Arabic we often use the phrase "don nadam" rather than "la nadam", however, it is confusing to translate "no remorse" without the context it is used in.