* Dollar index up after brushing three-week high
* Aussie lifted by stronger-than-expected jobs data
* Pound frail after weak inflation data, Brexit worries
* Graphic: World FX rates in 2018 tmsnrt.rs/2egbfVh (Adds quote, context, updates prices)
By Tom Finn
LONDON, July 19 (Reuters) - The dollar rose to a one-year high on Thursday as investors strengthened bets on the currency's long-term strength following upbeat comments on the U.S. economy by the Federal Reserve's chairman.
Jerome Powell did not alter expectations of U.S. monetary policy in his addresses to Congress on Tuesday and Wednesday, but traders saw his remarks as signifying that authorities were comfortable with the dollar's near six percent rise against its rivals in the last three months.
That represents a shift in the stance laid out by Treasury Secretary Steven Mnuchin, who in highly unusual remarks in January said a lower dollar was "good for us".
A weaker dollar would help American exporters compete abroad but it may undermine its status as the world’s top reserve currency.
On Wednesday, Powell said he believed the United States was on course for years more of steady growth, and carefully played down the risks to the U.S. economy of an escalating trade conflict.
The dollar index versus a basket of six major currencies on Thursday jumped half a percent to 95.557, its highest since last July.
That put pressure on the euro which sank 0.4 percent to a two-week low of $1.1586.
Meanwhile, the widening trade rift between China and the United States knocked the yuan to a one-year low in both the onshore and offshore markets.
The yuan has weakened six percent since June 15 when U.S. President Donald Trump said he was pushing ahead with hefty tariffs on $50 billion of Chinese imports.
"The Fed Chair does not appear to be overly concerned about the flatter yield curve and the central bank is signalling further interest rate increases. We see limited potential for a near-term turnaround in dollar strength," said Chris Turner, head of currency strategy at ING in London.
Though concerns remain the U.S. economy may be nearing a peak as evident from a flattening yield curve, the widening rate differentials between the United States and other major markets have lifted the dollar.
The two-year Treasury yield stood near 2.624 percent, its highest since August 2008 scaled on Wednesday.
"We are firmly of the view that broad-based USD strength can continue. Powell’s testimony signalled there is no intention of changing its policy of gradual interest rate hikes. In addition, risks remain around the outlook for emerging markets," analysts at Rabobank said in a note.
The Fed has been ahead of its peers in tightening monetary policy and is expected to have raised rates a total of four times in 2018 to tackle rising inflationary pressures.
With U.S. rates continuing to rise and most other major central banks taking only tentative steps towards monetary normalization, many analysts expect more dollar upside. RBC is forecasting a year-end euro/dollar of $1.12.
Against the Japanese yen, the dollar was down 0.1 percent at 112.995 yen. The dollar on Wednesday rallied to as high as 113.14 against the yen, its strongest since January 9.
China's Ministry of Commerce said on Wednesday it would have to take further measures to compensate for losses caused by U.S. tariffs on steel and aluminium
U.S. President Donald Trump's top economic advisor, Larry Kudlow, also said on Wednesday that he believed Chinese President Xi Jinping has blocked progress on a deal to end duelling U.S. and Chinese tariffs.
Amid the simmering trade tensions, the Chinese yuan extended losses to touch a one-year low of 6.8027 per dollar in offshore trading.
The Australian dollar gained on a stronger-than-expected local June employment data.
Sterling slumped on weaker than expected retail sales data which cast doubt on the chances of a central bank interest rate hike next month. Political turmoil related to Britain's plans to leave the European Union has also served as a lingering drag on the pound.
The pound fell to $1.2974, a fresh 10-month low.
Editing by Larry King, William Maclean