"My thoughts go to Jerusalem and I can not keep silent my deep concern for the situation that has been created in the past days", the pontiff said during the weekly General Audience at the Vatican.
In a tweet this morning, Cardinal Nichols urged people to "heed again the words of Pope Francis: Jerusalem is a "unique city" that has "a special vocation for peace". "At the same time, I appeal strongly for all to respect the city's status quo, in accordance with the relevant United Nations resolutions", the Pope said in his weekly address, reports AFP.
Pope Francis said he was "profoundly concerned" and appealed for the status quo of Jerusalem to be respected and for "wisdom and prudence" to prevail.
Trump's decision has been strongly condemned by United States allies and rivals alike.
The Turkish government said the expected U.S. move risked igniting a "fire" in the Middle East and would prove a "great disaster".
West Jerusalem is where Israel's government is based, but Palestinians view East Jerusalem as the capital of a future Palestinian state.
Before making his public comments, Francis met privately with a group of Palestinians involved in inter-religious dialogue with the Vatican.
"I pray to the Lord that this identity would be preserve and strengthened for the benefit of the Holy Land, the Middle East and the whole world and that wisdom and prudence would prevail, to avoid adding new elements of tension in a world already shaken and marked by many cruel conflicts". It has been the capital of the Israeli people since ancient times.
Mr Abbas is also understood to have called Pope Francis to express his concerns about the move.
The Holy See recognized the Palestinian state in 2015.
Trump is expected to formally recognize Jerusalem as Israel's capital on Wednesday and begin preparations to move the U.S. Embassy to the city, three senior administration officials confirmed late Tuesday.
Trump will make the announcement in a speech Wednesday - which will be closely watched by other world leaders who fear the move will undermine peace negotiations between Israelis and Palestinians and spark protests across the Middle East.