New York and London are covered by the British Broadcasting Corporation.
The stock markets in the US ended the week down after comments by the Federal Reserve.
The bank needs to keep raising interest rates to stop inflation from becoming a permanent aspect of the US economy, according to the chairman.
His words caused the US stock market to fall 3%.
Americans are having to pay more for basics.
The world's largest economy has a high inflation rate.
During a highly anticipated speech at a conference in Wyoming on Friday, Mr Powell said the Federal Reserve would probably impose further interest rate hikes.
A sustained period of below-trend growth is likely to be required to reduce inflation.
If economic growth slows, investors are worried that interest rates will go up.
Mr Powell said that getting inflation under control would cost American households and businesses, but that it was worth it.
He said that higher interest rates, slower growth and softer labour market conditions will bring some pain to households and businesses.
The costs of reducing inflation are unfortunate, but a failure to restore price stability would be worse.
Mr Powell doesn't want inflation to become entrenched. If people think inflation will be high, they will change their behavior, which will make it a prophecy. A person who thinks prices will go up 3% next year is more likely to get a 3% wage increase.
The last time this happened, Mr Powell's predecessor, Paul Volcker, had to raise interest rates and cause the economy to go into recession.
In March, the Federal Reserve's key interest rate was almost zero; it has since been raised to a range of 2% to 2.5%.