While few details were expected to emerge from the private talks, Abdullah and Merkel were to discuss developments between Israelis and Palestinians ahead of a peace conference due to take place this month in the American city of Annapolis, Maryland, government spokesman Thomas Steg said.

"The German government hopes and expects that the Annapolis meeting will contribute to a breakthrough," Steg said ahead of the meeting.

The leaders also planned to discuss the effects developments in Iran could have "on the Islamic world and on the stability of Afghanistan and Pakistan," he added.

Riyadh is pushing a Middle East peace plan it drew up five years ago which was revived at an Arab summit in Saudi Arabia in March. It offers Israel peace and normal ties if it withdraws from all land seized in the 1967 Six Day War and allows the creation of a Palestinian state and the return of Palestinian refugees.

Observers have said Saudi Arabia could work as a mediator between the Palestinians and Israelis, if Riyadh and the West speak with a united voice.

Merkel, Bush push diplomacy

Merkel's meeting with the king comes before her talks with US President George W. Bush in Texas, whom she is expected to brief on what she heard from Abdullah. Merkel has said she will urge Bush to find a diplomatic solution to the Iranian nuclear crisis.

"I want a diplomatic solution and I will make every effort to achieve it," Merkel said in an interview with the daily Berliner Zeitung. "I am sure that the US president will lend me his ear."

Friday's meeting between Bush and Merkel will come on the heels of an announcement from Iran that its nuclear program reached a key milestone Wednesday of 3,000 centrifuges operating to enrich uranium.

The number is important because scientists say that in ideal conditions it is sufficient to produce enough enriched uranium in one year to make a nuclear bomb. The International Atomic Energy Agency confirmed in August that Iran had 1,968 running to enrich uranium and that 656 others were either under construction or being tested. It is unclear when it obtained the remaining centrifuges.

Iran maintains energy production is the sole goal of its nuclear program while the West says the country may be working toward creating nuclear weapons.

Key role for Germany, support from France

Bush said Germany would play an important role in reaching a peaceful solution with Tehran.

"We definitely need Germany's help in problems like Iran so that we can solve the situation diplomatically," he said Wednesday in RTL/n-tv television interview. "That's going to be an important topic with the chancellor."

Washington insists it wants a diplomatic solution, but at the same time has not ruled out a military option. Bush has said "World War III" and a "nuclear holocaust" could arise from Iran acquiring nuclear weapons.

The standoff with Iran also played an important role in discussions between Bush and French President Nicolas Sarkozy on Wednesday.

The French leader affirmed his strong support of the US drive to deprive Iran of atomic weapons, saying to applause during a joint session of US Congress that "the prospect of a nuclear-armed is unacceptable to France."

"Iran must be persuaded to choose the option of cooperation, dialogue and openness ... we will be firm and we will keep up the dialogue," he said.