The monarch flew into Israel by helicopter on Thursday and spent several hours in talks with Sharon before returning home, a palace official said on Friday.
"The visit was meant to allay King Abd Allah's fears that construction of the fence will prompt a flight of Palestinians over the border into Jordan," a senior political source said about Israel’s barrier cutting off parts of the occupied West Bank and now under World Court scrutiny.
Amman, which signed a peace treaty with Israel in 1994, settled a large number of Palestinians forced out of their homes when Israel was created in 1948 and again in the 1967 Israeli-Arab war.
The concrete barrier separates thousands of Palestinian farmers from their land, schools and hospitals. Jordan fears another exodus from the West Bank if the barrier makes life impossible for Palestinians.
Israeli sources said Sharon promised the king to block any such mass movement.
Israel says the barrier is necessary to prevent the infiltration of Palestinian resistance fighters but Palestinians fear the bulwark of wire and concrete snaking into the West Bank is a land grab. They also fear it will demarcate the borders of a future Palestinian state.
Sharon's meeting with the king was his first with an Arab leader since a Middle East summit in Aqaba, Jordan last June that adopted a US-backed "road map" aimed at ending the Palestinian-Israeli conflict.
Palestinians fear the barrier is
aimed at taking more land
Sharon’s brutal crackdown on the Palestinians as they wage the Intifada or uprising against continued occupation have added to his unpopularity in the Arab world, making any meetings with him politically risky for leaders.
Meeting at the Sycamore ranch in southern Israel, King Abd Allah and Sharon also discussed the prime minister's plan to "disengage" unilaterally from the Palestinians if the "road map" is not implemented, the source said.
Under the plan, Israel would dismantle Jewish settlements in the occupied Gaza Strip but Palestinians fear it would take over parts of the West Bank.
Under international law, all Jewish settlements are illegal, a stance not recognised by Israel.
On the ground, a powerful bomb exploded near an Israeli tank in the Gaza Strip, overturning it and wounding two soldiers during a raid on the village of Mughraqa. Hamas said it planted the explosives.
Israeli occupation forces also blew up the family home of a dead Hamas fighter and wounded seven Palestinians during the invasion.
Youths threw pipe bombs at several invading tanks while helicopter gunships fired.