At a previous meeting in March last year the commission reasserted the Vatican's wish for "constructive dialogue" with China, which has no relations with the Holy See and has set up its own official "patriotic" Church.
The pope's strongly worded letter to the eight to 12 million Chinese Catholics loyal to Rome said the communist regime should respect their "authentic religious freedom" and warned that the official church was "incompatible with Catholic doctrine."
The letter also expressed the hope for "a respectful and open dialogue" between the Vatican and Beijing.
China immediately rebuffed the appeal and urged the Vatican to refrain from creating new barriers to improved relations.
Beijing severed ties with the Vatican in 1951 in anger at the Holy See's diplomatic recognition of Taiwan, which Beijing views as a renegade province.
In 1957, the split became permanent when China set up the Patriotic Association to formally oversee the country's officially registered Catholics.
The association counts about five million members, while the Vatican estimates that as many as eight million believers practise their faith in secret and are subject to persecution.
The Vatican says it will abandon ties with Taiwan in favour of Beijing if China guarantees religious freedom and allows the pope to name Chinese bishops.
Beijing has imposed two conditions on the restoration of ties -- the Vatican's recognition of the one-China policy that precludes independence for Taiwan and its acceptance that religious affairs are an internal Chinese matter.
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Image from www.missouristate.edu/china/