Beijing has been accused of committing “crimes against humanity" against the Uyghur Muslims and other ethnic minority groups over the past decade through alleged widespread abuses, including mass incarceration, forced labour, torture and sexual assault.
The United States along with other Western countries have labelled China's policies as a "genocide", a claim that Beijing has denied and dubbed “the lie of the century.”
Mr Xi on Saturday travelled to the regional capital of Urumqi for the first time since his first publicly known visit to Xinjiang in July last year.
The Chinese president listened to government work reports and delivered a speech "affirming the achievements made in various tasks in Xinjiang", state broadcaster CCTV reported.
Stability in Xinjiang is also key to increased local economic development, Mr Xi said during his visit, adding that the region can promote resources-based industries and is encouraged to build more agricultural and solar industrial parks.
He said it was "necessary to... combine the development of the anti-terrorism and anti-separatism struggle with the push for normalising social stability work and rule of law”.
According to reports, Mr Xi also urged officials to "more deeply promote the Sinicisation of Islam and effectively control illegal religious activities".
"In the process of Chinese-style modernisation, we will better build a beautiful Xinjiang that is united and harmonious, wealthy and prosperous."
The president added that officials must “strengthen positive publicity and show Xinjiang’s new atmosphere of openness and self-confidence... (while) refuting all forms of false public opinion and negative or harmful speech”, according to the state broadcaster.
A 48-page report released by the UN in September last year said a million or more people from minority groups were forced into detention camps where many have said they were tortured, sexually assaulted, and forced to abandon their language and religion.
It said that descriptions of the detentions were marked by patterns of torture and other cruel and inhuman treatment and said that allegations of rape and other sexual violence appear credible.
“The extent of arbitrary and discriminatory detention of members of Uyghur and other predominantly Muslim groups ... in [the] context of restrictions and deprivation more generally of fundamental rights ... may constitute international crimes, in particular crimes against humanity,” the report said.
Beijing has closed many of the camps, which it called vocational training and education centres, but hundreds of thousands of people continue to languish in prison, many on vague, secret charges.
The UN assessment said that reports of sharp increases in arrests and lengthy prison sentences in the region strongly suggested a shift toward formal incarceration instead of the use of the camps.