The rights of religious groups, particularly Christians, have been squeezed under Communist Party President Xi Jinping.
Charities working in the region such as China Aid and Christian Solidarity Worldwide have continued to raise concerns about the process of cross removal and the arrest of church leaders and lawyers defending religious freedoms.
The US Commission on International Religious Freedom (USCIRF) has asked the US president to address the lack of religious freedoms in the country and urge the release of religious prisoners.
The G20 summit begins on 4th September in Hangzhou, in Zhejiang Province, in eastern China.
The US Commission on International Religious Freedom said that: "As the Chinese government aggressively asserts itself on the global stage, at home it aggressively violates the human rights and religious freedom of its citizens."
Chairperson Thomas J Reese went on: "While these violations have intensified in Zhejiang Province, the location of the G20 Summit, they also are taking place throughout China as the government seeks to repress the voices of individuals and groups advocating for their rights."
The province is home to a significant Christian population and the Chinese government says that 'safety concerns' have led to the closing down of unregistered churches and Christian meetings ahead the meeting of world leaders.
The G20 summit lasts two days and economic powers from across the world will discuss their futures together.
Tania Corbett from Open Doors told Premier's News Hour that she hopes the Prime Minister Theresa May will address this when she arrives for the G20 talks.
She said she wants the PM to "reiterate the government's commitment to the United Nations Article 18, which ensconces (ensures) freedom of religious belief or people, and to keep that at the centre of negotiations with China."
Tania Corbett went on: "We've seen Christian pastors imprisoned, there's also been a campaign of the removal of crosses from various churches, which initially it was thought that was to do with building regulations, and then it seemed to be the interpretation of different policies in different areas."
"There seems to be a growing intolerance towards the lawyers who've been defending the churches who's crosses were removed," she said.
Listen to Premier's Aaron James speak to Tania Corbett here: