Question

the state parties have the responsibility for identifying and nominating ne sites (use noun forms of the underlined words and rewrite the sentence)

Answer 1

Identification and Nomination...

Answer 2

Missing question parts

The underlined words are 1) identifying and 2) nominating.

The answer is "the state parties have the responsibilities of identification and nomination of new sites."  

Explanation

Noun: It is the name given to person, place, thing or an act.

Identifying and nominating are gerunds or present participles.

The noun form of identifying is identification.

The noun form of nominating is nomination.