Yen falls near two-week lows after Japan's verbal warnings

The yen fell to its lowest in almost two weeks against the US dollar on Tuesday following warnings by Japan that it was prepared to step in to weaken the currency.

The dollar rose 0.4% to a 12-day high of 108.895 yen, after surging more than 1% on Monday. The US currency tumbled to an 18-month low of 105.55 yen last week after the Bank of Japan (BOJ) stood pat on monetary policy.

Finance Minister Taro Aso said on Monday that Tokyo was ready to intervene to weaken the currency if moves were volatile enough to hurt the country's trade and economy. He reiterated that message on Tuesday.

Traders said some speculators were cutting favourable bets on the yen, having piled into the currency in the past few weeks. 

"Considering that speculative long positioning remains relatively sizeable, such comments should increase uncertainty among all those who remain long," said Manuel Oliveri, currency strategist at Credit Agricole. "We do not exclude further position squaring-related downside risks."

Nevertheless, many believe the bar for intervention is high and unless the yen strengthens rapidly past 105 and towards the 100 mark against the dollar, authorities are likely to stay on the sidelines. 

"Japanese authorities will obviously never state what currency levels are important to them, but if you can read between the lines, 105 yen seems to be one of the watersheds," said Bart Wakabayashi, head of FX sales at State Street Global Markets in Hong Kong.

Traders said Japan will also be wary of intervention before it hosts a G7 meeting later this month. Attendees at previous G7 meetings have frowned upon interventions, and Tokyo is sensitive to criticism that it is trying to engineer a weaker yen.

A recent US Treasury report termed countries with substantial trade surpluses such as Japan which try to weaken their currencies through "persistent one-sided" intervention as manipulators. 

The euro rose 0.45% to a near two-week high of 124 yen, pulling further away from a three-year trough of 121.48 plumbed late last week.

The common currency was flat against the US dollar at $1.1385 . The dollar index DXY was at 94.151, having hit its highest in nearly two weeks in the Asian trading session and extending its rise from a 15-month trough reached on May 3.