Here Nephi continues his discussion of the future history of the House of Israel with the definition of a covenantal promise. The Lord reiterates that he will remember the covenants which he made to Israel, but only at such time as they no longer turn aside their hearts. While directed to the Israel, this admonition applies to all who make covenants with the Lord. He will always remember his part of the covenant, upon the condition that we remember ours.
It is worth noting in passing that "remember" in the scriptures has more to do with action than simple cognition. The Lord does not ask us to simply remember our covenants, but to live up to them. Remembrance in the scriptures is involved with the action, not the thought.