Envoys said Jordan had been reluctant to take up the Asia-Pacific seat on the 15-nation council but had been persuaded by the Saudis.
Jordan's UN ambassador Prince Zeid al-Hussein returned to Amman on Thursday for consultations on the surprise move, one UN diplomat said.
"Jordan came under a lot of pressure to take the seat," added a second diplomat who confirmed the news. Jordanian diplomats made no immediate comment.
Saudi Arabia won a UN General Assembly vote on October 17 for a two-year term on the council. But it shocked other countries by announcing the following day that it would not take up the seat in protest at the council's failure to act on the Syria conflict.
Saudi Arabia is still expected to get a seat on the UN Human Rights Council in a vote next week. Jordan is again involved.
Jordan withdrew from the campaign for a rights council place this week. That left the way open for Saudi Arabia, China, Maldives and Vietnam to take the four Asia-Pacific seats on the council to be decided in a General Assembly vote on November 12.
BA/BA