Critics of the deal, including Zen, warned that the underground Church would not be sufficiently protected from the Chinese government's efforts to impose its ideology on to all religions in the country, including Catholicism.
A report by the Congressional China Commission, issued in January, noted that human rights abuses intensified in China during the 2019 reporting year, and the persecution of Catholics worsened after the Vatican-China deal was reached.
"More and more, the Church [is] under persecution," Zen said on Tuesday, "both the official Church, and the underground."
The underground Church, he said, "is doomed to disappear," as older bishops loyal to the faith are dying and no new bishops are being appointed - meaning no new priests can be ordained.
Zen said that Chinese Catholics come to Hong Kong from the mainland to ask what he can do for the Church in China. "I can do nothing. I have no voice in the Vatican. Simply not," he told CNA.
"And so the situation is, humanly speaking, hopeless, for the Catholic Church," Zen added.
Zen is the bishop emeritus of the Diocese of Hong Kong, the special administrative region has seen nearly a year of pro-democracy protests, beginning with opposition a bill to allow for the extradition of individuals from Hong Kong to mainland China. The protests have also focused on protecting Hong Kong's special status against perceived increasing influence and control by the mainland Chinese government. The extradition bill was eventually pulled from consideration.
Recently, CNA reported that a candidate for the next bishop of Hong Kong had been settled upon by the Vatican, but that the announcement was delayed because the candidate would be seen as too sympathetic with the mainland Chinese government. Fr. Peter Choy Wai-man was reportedly picked to succeed Bishop Michael Yeung Ming-cheung, who died unexpectedly in January of 2019.
Since that time, the diocese has been administered by Cardinal Zen's immediate successor, Cardinal John Tong Hon, who retired in 2017. CNA also reported that the Vatican's first choice as the new bishop of Hong Kong, current auxiliary of the diocese Bishop Joseph Ha Chi-shing, had his appointment dropped before being announced after he was pictured taking part in street protests against the government.
At the request of Cardinal Zen, no photographs were taken of the cardinal's visit to the U.S. Capitol, which included his interview with CNA.