* Platinum hits over two-month highs
* Dollar index slides to 5-week low
* Fed's Yellen to host webcast meeting on Thursday (Updates prices; adds comment, second byline, NEW YORK dateline)
By Marcy Nicholson and Eric Onstad
NEW YORK/LONDON, Jan 12 (Reuters) - Gold surged above $1,200 an ounce to its highest in seven weeks on Thursday as the dollar fell after U.S. President-elect Donald Trump's long-awaited news conference gave few details on economic policy.
But analysts warned that gold's revival since mid-December may be running out of steam as the dollar was likely to rebound once Trump moves ahead with his economic plans.
Spot gold XAU= was up 0.5 percent at $1,197.64 an ounce by 2:35 p.m. EST (1935 GMT), after touching $1,206.98, its loftiest since Nov. 23. U.S. gold futures GCcv1 settled up 0.3 percent at $1,199.80 per ounce.
Trump delivered a wide-ranging briefing on Wednesday that lasted longer than expected but contained no details on tax cuts and infrastructure spending, analysts said. sent the dollar index .DXY sliding to the lowest in nearly five weeks. USD/
"It's a mess frankly, which is a reflection of the fact that there's no clarity on U.S. economic policy," said Tom Kendall, head of precious metals strategy at ICBC Standard Bank.
"For the time being, I'm sticking to my thesis that this move can go a bit further, but we're running out of steam."
Gold is up around 7 percent since hitting a 10-1/2-month low on Dec. 15.
"Despite moving back to $1,200 per ounce, we see no lasting recovery for gold," said Carsten Menke, commodities research analyst at Julius Baer in Switzerland.
"The market lacked support from physical buying ... which we believe is a precondition for a lasting recovery."
The outlook for U.S. rates may become a little clearer when Federal Reserve Chair Janet Yellen appears at a webcast town hall meeting with educators on Thursday. election has introduced a proliferation of unknowns, which the market will have to work through as they surface," RBC Capital Markets said in a note.
"Overall, while we are cautiously optimistic on gold for the year, we still think the real reason to buy gold is as a risk overlay - a hedge against moves like these."
Spot silver XAG= was up 0.4 percent at $16.79 an ounce after hitting a four-week high of $16.98.
Platinum XPT= climbed 0.6 percent to $978.30, after touching a high of $990.10, its strongest since Nov. 10.
Palladium XPD= added 0.5 percent at $758.
Commerzbank (DE:CBKG) said Chinese car sales were not likely to match their 2016 record-high gain of 15 percent.
"The sales dynamism is expected to decline significantly in 2017 ... platinum group metals, and particularly palladium, are therefore likely to be not quite as well supported this year," a note said.