Yellen hints that the United States will not stop Japan from intervening in currency markets, and the U.S. economy needs to slow down

US Treasury Secretary Janet Yellen said:It would be understandable if Japan intervened to support the yen in order to calm volatility, rather than to influence the level of the exchange rate。

"It depends a lot on the details," Yellen said on Tuesday when asked if Japan intervenedforeign exchange marketWhether the US Treasury would understand the yen purchases, "we usually communicate with them about these interventions."

In recent weeks, Japanese officials have expressed growing concern about the weakness of the yen, which has hurt households and retailers by boosting profits for Japanese exporters but increasing the cost of imported raw materials and fuel. The yen has been hovering near a 10-month low against the dollar. Earlier this month, Japan issued its strongest warning in weeks about sharp currency swings, raising the prospect of government intervention in the event of a persistently weak yen.

Ms Yellen was speaking to reporters on the sidelines of the UN General Assembly in New York, where the G7 has long insisted that letting markets determine exchange rates is a fundamental principle.

The Japanese government intervened to prop up the yen for the first time since 1998 after the yen plunged about 20 per cent against the dollar last year, as hedge funds ramped up their bets against the currency. Many in the market see 150 as Japan's floor, a break that could trigger a new round of intervention.

The US economy needs to slow down

Industrial foreign exchangeThe US economy needs to slow to a level more in line with its potential growth rate to bring inflation back to target because the economy is at full employment, she said, adding that the imbalance between supply and demand in the labour market had eased.

"Growth has to slow down. I mean, when you're operating at full employment, you want growth to slow down, you want it to be in line with potential," Yellen told reporters on the sidelines of a climate event on Tuesday. "The pace of growth is slowing, which is completely natural and desirable."

Yellen did not specify what the potential growth rate would be, other than to say that economic growth has been above that level. She also said that surveys of companies show that,The demand for labor has weakened, which has helped to lower core inflation。

Yellen warns of "significant economic losses" from climate change

Ms Yellen announced a set of voluntary "principles" to encourage the private sector to put more money into climate and clean energy projects and to crack down on "greenwashing" in response to what she called the "huge economic damage" from global warming.

She warned that record heat waves and unprecedented wildfires could become major headwinds for the economy.

Yellen said climate change presents investment opportunities for U.S. companies, citing studies estimating that more than $3 billion a year, including in the U.S., will be needed to reduce emissions between now and 2050.

Meanwhile, the heads of state of 17 countries, including France, Spain, Denmark and Kenya, said investments in technologies such as carbon capture and storage, which have yet to be deployed on a large scale but which fossil fuel producers rely on to justify new projects, would play only a "minimal" role in decarbonising the energy system.

Ms Yellen also stressed that the Financial Institutions Group's commitment to net zero greenhouse gas emissions should promote "consistency and credibility". "If these factors are not taken into account, the Financial Institutions Group risks being left behind with stranded assets, outdated business models and missed opportunities to invest in a growing clean energy economy," she said.

Yellen met with financial executives, including BlackRock CEO Larry Fink and HSBC CEO Noel Quinn, to discuss the measures.