(Reuters) - U.S. banks have reaped a windfall from higher interest payments on loans, but commentary from some top executives suggests they could face an uncertain path ahead.

Waning demand from borrowers and slowing consumer spending could weigh on bank earnings in the coming months.

Here are some comments from earnings season so far:

JPMORGAN CHASE ( JPM ) -

"While market valuations and credit spreads seem to reflect a rather benign economic outlook, we continue to be vigilant about potential tail risks," CEO Jamie Dimon said.

"Loan demand remains quite muted everywhere except card," CFO Jeremy Barnum said on a call with analysts, referring to credit cards.

BANK OF AMERICA ( BAC ) -

"Consumer led the way in delivering solid organic growth with high quality accounts and engaged clients," CEO Brian Moynihan said.

"We expect net interest income (NII) will begin to rise in Q3 compared to Q2, and it will then rise again in Q4," CFO Alastair Borthwick said.

WELLS FARGO ( WFC ) -

"Consumers have benefited from the strong labor market and wage increases," said CEO Charles Scharf.

"Customer migration to higher-yielding alternatives was also lower in the quarter," said CFO Mike Santomassimo.

CITIGROUP ( C/PN ) -

"There are clear signs of a softening labor market and the tightening of the consumer budget," CEO Jane Fraser said.

"We have the higher FICO score customers that are driving the spend growth and that, frankly, have still continued strong balances and savings and it's really the lower FICO band customers where we're seeing the sharper drop in payment rates and more borrowing," CFO Mark Mason said.

PNC FINANCIAL SERVICES ( PNC ) -

"NII and net interest margin increased, marking the beginning of our growth trajectory towards expected record NII in 2025," said CEO Bill Demchak.