Malia Bouattia has insisted that Jewish students can choose their own anti-racism representative, but has fallen short of involving the Union of Jewish Students (UJS).
But UJS representatives have said the NUS president has not gone far enough in allaying their concerns.
Last week the National Union of Students (NUS) voted against a proposal to enable UJS to help choose a Jewish representative for the union's Anti-Racism Anti-Fascism (ARAF) committee.
Instead, it stated that the 39 members of the union's national executive would vote on who takes up the role - with no input from the Jewish student body.
Following the decision, Izzy Lenga, a Jewish member of the union's National Executive Committee, described the NUS as "toxic" for Jewish students.
The 8,500 Jewish students will not get a say who represents them
But in a letter to the Cambridge University Students Union (CUSU) this week, Ms Bouattia appeared to have softened the union's position by announcing that she has "issued an interpretation of policy which will ensure that representatives of the committee will be elected autonomously by self-identifying caucuses".
The announcement came in a long-anticipated response to a letter from CUSU, in which former students' union president Priscilla Mensah called on NUS to "do more to protect the rightful place of Jewish students within the student movement".
Ms Bouattia wrote: "As your president I intend to fight for the rights and safety of all students, including Jewish students. I want to reiterate that I and the NUS full time officer team, believe there is no place for any form of racism, including antisemitism, in NUS, or across the student movement. I know you and our members will hold us to account for upholding this belief in all that we do."
But this fell short of what Jewish students want in order to feel reassured, according to Josh Nagli, campaigns director for UJS.
Mr Nagli said: "The 8,500 Jewish students in Britain will still not get a say in who represents them. This post will probably be given to a Jewish student on the executive who has not been elected and therefore cannot be held to account."
In her letter Ms Bouattia said that she had met UJS representatives, but Mr Nagli claimed that she has made no advances towards the organisation since their only meeting when she was first elected earlier this year.
He said she had not adequately to addressed the concerns of Jewish students, describing the situation as "quite concerning".