TOKYO, Aug 22 Reuters The U.S. dollar eased back from a 10week peak versus major peers on Tuesday, even as Treasury yields marched to fresh postfinancial crisis highs, as traders awaited a potentially crucial speech from Federal Reserve Chair Jerome Powell later this week.

The yen pulled away from a ninemonth trough after Bank of Japan Governor Kazuo Ueda met with the prime minister, although he said exchangerate volatility was not discussed.

China39;s yuan briefly popped to a oneweek high as the central bank again tried to bolster the currency by setting a much strongerthananticipated daily midpoint, but those gains fizzled out quickly.

The U.S. dollar index which measures the currency against six developedmarket counterparts, including the yen and euro slipped 0.14 to 103.18, but remained not far from Friday39;s high of 103.68, a level not seen since June 12.

Surging longterm U.S. yields and the underwhelming response by China39;s policymakers to ongoing stresses in China39;s property and financial markets continue to provide bullish impulse to the U.S. dollar, Richard Franulovich, a currency strategist at Westpac, wrote in a note.

If Chair Powell keeps the door ajar to rate hikes, in his speech on Friday at the central bank39;s annual symposium in Jackson Hole, Wyoming, a new front for US upside can form, with the dollar index potentially breaking above 104, he said.

Benchmark 10year U.S. Treasury yields pushed to the highest since November 2007 at 4.366, as…