Hamas chief Khaled Meshaal has arrived in Jordan on his first official visit since his expulsion in 1999.
Mr Meshaal, whose visit comes after Qatari mediation, arrived in Amman with Doha's crown prince, Sheikh Tamim bin Hamad al-Thani.
King Abdullah II is expected to meet Mr Meshaal and Sheikh Tamim and a five-member delegation of the Hamas political bureau, including number two Musa Abu Marzuk, who arrived in Amman on Saturday.
Mr Meshaal, who has Jordanian nationality, "will make a statement to the press before he and the crown prince of Qatar leave Jordan," added the source.
The palace issued a short statement, saying only that Sheikh Tamim will be accompanied by Mr Meshaal on a one-day trip.
A senior Jordanian official called it a "protocol visit".
But Jordan's powerful opposition Islamists, who are ideologically close to Hamas, called Mr Meshaal's visit "historic."
"The meeting today is historic. Qatari mediation is supporting the palace's efforts to reformulate Jordan-Hamas relations in line with national interests," the Muslim Brotherhood said on its website.
Hamas spokesman in Gaza Sami Abu Zuhri has said the visit seeks to "boost political cooperation, reorganise ties with Jordan and study the means to open a Hamas office in Amman".
"The trip is also aimed at facing Israeli schemes to abolish Palestinian refugees' right of return and turn Jordan into a substitute homeland for Palestinians," Mr Abu Zuhri said on Tuesday.
