* Markets calm somewhat as US official calls strike a "one-off"
* Safe-havens yen, gold, Treasuries climb
* Asia shares, S&P 500 futures down as investors avoid risk trades
* European stock markets also set to open lower
By Nichola Saminather and Wayne Cole
SYDNEY, April 7 (Reuters) - Bonds, gold and the yen jumped in Asia on Friday, while stocks retreated, as investors fled to safe assets after the United States launched cruise missiles against an airbase in Syria, raising the risk of confrontation with Russia and Iran.
The U.S. dollar dropped as much as 0.6 percent, while gold and oil prices rallied hard, though the early market panic ebbed when a U.S. official called the attack a "one-off", with no plans for escalation.
"It was a knee-jerk reaction because markets are starting to come back a little, as it doesn't seem like there will be further retaliation coming," said Christoffer Moltke-Leth, head of institutional client trading at Saxo Capital Markets in Singapore.
European stocks were also poised for a negative start, with financial spreadbetters expecting Britain's FTSE 100 and France's CAC 40 to open down 0.2 percent, and Germany's DAX to start the day 0.3 percent lower.
U.S. President Donald Trump ordered the strikes on Thursday against an airbase controlled by Syrian President Bashar al-Assad's forces in retaliation for a chemical attack, launched from the base on Tuesday, that killed at least 70 people.
Facing his biggest foreign policy crisis since taking office in January, Trump took the toughest direct U.S. action yet in Syria's six-year-old civil war.
A Syrian human rights monitor said the missile strike had almost completely destroyed the airbase near Homs, and the city's governor said five had been killed and seven wounded. While U.S. allies including Britain, Australia and Saudi Arabia, as well as Syria's opposition group, welcomed the move, Russia and Iran condemned the attack.
A Russian lawmaker said the nation would call for an urgent meeting of the United Nations Security Council, adding the strikes could be viewed as an "act of aggression" against a U.N. member.
"The action adds a complexity to geopolitics that wasn’t there before, given Russia’s support for Syria and Trump's pre-election pledges to try and repair relations with (Russian President Vladimir) Putin," Michael Hewson, chief market analyst at CMC Markets in London, wrote in a note.
"The U.S. would now appear to be on a collision course with Russia."
MSCI's broadest index of Asia-Pacific shares outside Japan was down 0.4 percent after earlier sliding as much as 0.85 percent to a 2-1/2-week low. The index is set to end the week down about 0.2 percent.
E-mini S&P 500 futures lost 0.3 percent, having earlier tumbled as much as 0.7 percent, in unusually sharp moves for Asian hours.
But Japan's Nikkei reversed course to close up 0.4 percent, narrowing losses for the week to 1.3 percent.
Secretary of State Rex Tillerson noted the attack was "proportionate", suggesting no follow-up was planned.
"The unexpected and unequivocal nature of the U.S. response to the sarin-centric carnage in Syria by President Trump was very much in keeping with his promise not to telegraph his military options to the world in advance of taking action," wrote Peter Kenney, senior strategist at Global Markets Advisory Group in New York.
Investors had already been on edge with Trump set to begin talks on Friday with Chinese leader Xi Jinping over flashpoints such as North Korea and China's huge trade surplus with the United States.
Markets are also bracing for U.S. non-farm payroll data for March later in the session, with economists forecasting a significant drop in job gains from February.
The yen, a favoured haven in times of stress, climbed across the board. The dollar moderated losses, last trading at 110.635 yen, after earlier touching 110.14, its lowest since March 28.
The dollar was otherwise steady against a basket of currencies at 100.63, as it benefited from flows into safe-haven U.S. Treasuries.
Yields on 10-year U.S. Treasuries fell as much as five basis points to 2.289 percent, its lowest level since November, briefly breaking a significant chart barrier at 2.30 percent for the first time this year. It was last at 2.3069 percent.
Spot gold added 1.2 percent to $1,262.46 an ounce after earlier hitting its highest point since Nov. 10.
Oil prices soared more than 2 percent on concerns the military intervention could affect supplies, but pulled back a little as that possibility receded.
U.S. crude added 1.6 percent to $52.50 a barrel, after touching its highest in a month, putting it on track for a 3.8 percent gain this week.
Global benchmark Brent climbed 1.4 percent to $55.66, set to end the week up 5.4 percent.
The euro was trading at $1.0651, just a hair above its close on Thursday following comments by the European Central Bank head Mario Draghi that he sees no need to deviate from the ECB's stated policy path at least until the end of the year. (Reporting by Nichola Saminather; Additional reporting by Charles Mikolajszak; Editing by Shri Navaratnam and Will Waterman)