VATICAN CITY — The Vatican on Monday urged Catholics in China's underground and official churches to take urgent, practical steps at reconciliation and forgiveness.

A new Vatican document said the Chinese faithful shouldn't wait for a structural merger of the two churches before working together. Rather, they should begin undertaking common initiatives and sharing pastoral projects now.

"Times and ways may vary according to local situations, but the commitment to reconciliation cannot be abandoned," the document said.

Pope Benedict XVI has made improving often-tense relations with Beijing a priority of his papacy and has sought to unify the country's faithful under his wing. But there has been little tangible evidence of progress in his four-year effort, and the Vatican recently denounced a new wave of arrests of underground priests and bishops and accused Beijing of mounting obstacles to a dialogue with the Holy See.

China forced its Roman Catholics to cut ties with the Vatican in 1951, shortly after the officially atheist Communist Party took power. Worship is allowed only in state-backed churches, which recognize the pope as a spiritual leader but appoint their own priests and bishops.

Millions of Chinese, however, belong to unofficial congregations that are loyal to Rome. Underground priests and bishops have been harassed or arrested by Beijing authorities.

In 2007, Benedict sent a special letter to Catholics in China, praising the underground church but also urging the faithful to reconcile with followers of the official church.

The Vatican issued a compendium to that letter Monday in hopes of helping the faithful better understand the pope's intent.

The compendium is written in a series of questions and answers, with the answers quoting from the 2007 document. But it also includes some footnotes that go beyond what the pope originally wrote.

"It is by means of practical steps that spiritual reconciliation, including visible reconciliation, will gradually occur, which will culminate one day in the complete structural unity of every diocesan community around its one bishop and of every diocesan community with each other and with the universal church," reads one footnote.

The Rev. Bernardo Cervellera, whose Vatican-affiliated missionary news agency closely follows the plight of the Catholic church in China, said the Vatican issued the compendium to help the underground faithful negotiate dealings with the official church.

Previously, the underground church refused to collaborate with the official church. Cervellera says that in light of the pope's letter, now many Chinese Catholics believe some sort of relationship is necessary.