JP Morgan chief executive Jamie Dimon has warned the world may be facing “the most dangerous time in decades”.
Conflicts in Ukraine and Israel could hit energy and food prices, and global trade, the bank boss said.
Thousands have been killed in Israel and Gaza after an unprecedented attack by Palestinian militant group Hamas.
Speaking as the bank revealed its latest results, Mr Dimon said labour shortages and high government debt levels also posed risks to economies.
This meant an increased risk that “inflation remains elevated and that interest rates rise further from here”, he added.
Central banks have been struggling to bring down inflation by hiking interest rates.
In the US, consumer prices continued to rise in September, up 3.7% over the year, the same rate as in August.
Inflation also remains high in the UK – at 6.7% in the year to August, it is well above the Bank of England’s target of 2%.
JP Morgan is the biggest bank in the US. On Friday it reported a net income of $13bn in the third quarter.
Commenting on the current international conflicts, Mr Dimon said: “The war in Ukraine compounded by last week’s attacks on Israel may have far-reaching impacts on energy and food markets, global trade, and geopolitical relationships.
“This may be the most dangerous time the world has seen in decades.”