Filed at 4:12 p.m. ET
TEHRAN, Iran (AP) -- Iran and the United States are playing a complicated diplomatic game, jockeying for influence in Iraq as violence there spirals out of control, but there is one major wild card in dueling summits planned for coming days: Syria.
Vice President Dick Cheney was heading to Saudi Arabia for key talks with King Abdullah on Saturday, apparently looking for its influence and tribal connections help to calm Iraq.
President Bush is due to meet Iraqi Prime Minister Nouri al-Maliki in Jordan on Wednesday and Thursday, an unusual succession of trips that reflects U.S. determination to rally allies at a time when Washington is considering overhauling its Iraq policy.
But an especially violent week in Iraq threatened to overshadow the planned Bush-Maliki meeting.
After suspected Sunni insurgents slaughtered 215 people with a series of car bombs in Baghdad's Shiite Sadr City slum the day before, a top Shiite party on which al-Maliki relies for power threatened to walk out of the government if he meets with Bush in Amman.
Iran, meanwhile, was having its own diplomatic troubles.
It has been trying to organize a summit Saturday joining its president, Mahmoud Ahmadinejad, and the presidents of Iraq and Syria, in a bid to assert its role as the top regional powerbroker.
Iraqi President Jalal Talabani agreed to attend. But on Friday, he had to postpone his trip until Baghdad's airport -- closed in a security clampdown after the violence -- reopens, no sooner than Sunday. ''The Tehran visit is still on,'' he said. ''The airport will be closed tomorrow but if it opens after tomorrow we will go.''
It also appeared unlikely on Friday that Syria's Bashar Assad would participate at all.
A top official at Iran's presidency on Friday said Syria has not responded to Iran's invitation and that ''there is no plan for Assad visit to Tehran at least for the next 24 hours.'' He spoke on condition of anonymity because he was not authorized to talk to the press.
On Thursday, Iranian Foreign Minister Manouchehr Mottaki said there was no agreement yet on a three-way summit. ''We will announce such a summit as soon as it is finalized. Of course, this is a good idea and we welcome it,'' he said.
Syrian officials have been silent for days over whether Assad would attend, apparently to avoid embarrassing Iran with a direct rejection -- though the delay in Talabani's arrival could give Syria a chance to reconsider coming.
Iran is Syria's only close ally and a rejection would be an unusual snub, but Damascus may be more worried about angering the United States by joining Iran's overt attempt to assert itself in Iraq. Instead, Syria is likely looking further down the road to potential talks with Washington.
''Syria is after concessions from Washington. Assad wants doesn't want to annoy Washington,'' said Leila Chamankhah, an Iranian political analyst.
After the Democratic victory in U.S. midterm elections, the Bush administration is under increased pressure at home to approach Iran and Syria for help in Iraq. Such a step is believed to be one of the recommendations by a blue-ribbon panel on Iraq led by former Secretary of State James A. Baker III and former Rep. Lee Hamilton.
On the face of it, an Iranian-Syrian-Iraqi summit would fit into U.S. hopes that Iraq's neighbors will step in to help ease the bloodshed. Iran is believed to back Iraqi Shiite militias blamed in sectarian killings that have killed thousands this year.
But Iran has made clear that the summit aimed to assert its influence in Iraq on Tehran's terms, not Washington's. Iran's conservative Kayhan newspaper boasted on Wednesday that the gathering would ''shake the U.S. president.''
Syria is accused by the United States of turning a blind eye to Iraqi insurgents that use its territory as a base. Damascus denies this, but it could be looking to trade stronger action in return for concessions from the U.S.
At the top of Syria's concerns are Lebanon and Israel. Syria is seeking to regain influence in Lebanon but has been opposed by the United States and the U.S.-backed Lebanese government.
Syria also wants a resumption of the Arab-Israeli peace process that it hopes would bring the return of the Golan Heights, captured by Israel in 1967.
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AP correspondent Salah Nasrawi in Damascus and Lee Keath in Cairo contributed to this report