By Jason Lange

WASHINGTON U.S. President Joe Biden's popularity slipped this month to its lowest level since April, a Reuters/Ipsos poll showed, the latest data point raising concerns about the Democrat's re-election bid next year.

The two-day opinion poll, which ended on Saturday, showed 39% of respondents approved of Biden's performance as president, matching April's reading and down marginally from 40% in October and 42% in September. The poll had a margin of error of about three percentage points.

Biden is widely expected to face a November 2024 rematch with former President Donald Trump, the frontrunner for the Republican nomination. Other recent polls have pointed to a potentially close race between the two.

The share of poll respondents who rated "war and foreign conflicts" the No. 1 problem rose to 8% in November from 4% in October, a sign of unease over a sharp escalation in the Israel-Palestinian conflict.

It was the highest measure of concern about war since April 2022, when 9% of respondents cited it as their top concern during the early months of the Russia-Ukraine war.

A larger share - 20% - said the economy was the top concern. By comparison, 9% cited crime and 7% cited the environment.

Biden's public approval rating has held below 50% since August 2021, and this month's rating was close to the lowest levels of his presidency - 36% - seen in mid-2022.

The Reuters/Ipsos poll gathered responses online from 1,019 adults, using a nationally representative sample.

(Reporting by Jason Lange; Editing by Scott Malone and Alistair Bell)