U.S. President Joe Biden's public approval rating dipped to 39% in a Reuters/Ipsos poll on Monday, reinforcing nonpartisan election forecasters' expectations that his Democratic party was in for a drubbing in Tuesday's midterm elections.

The two-day national poll found that Americans' approval of Biden's job performance had dropped by one point, nearing the lowest point of his presidency.

Biden's unpopularity is helping drive the view that Republicans will win control of the U.S. House of Representatives and possibly the U.S. Senate as well on Tuesday.

The University of Virginia's Center for Politics on Monday forecast that Republicans would easily win a majority in the House, picking up a net 24 seats, and would eke out a slim majority in the Senate.

Control of even one chamber of Congress would give Republicans the power to bring Biden's legislative agenda to a halt.

Taking office in January 2021 in the middle of the COVID-19 pandemic, Biden's term has been marked by the economic scars of the global health crisis, including soaring inflation. This year, his approval rating drifted as low as 36% in May and June.

In this week's Reuters/Ipsos poll, about a third of respondents picked the economy as the country's biggest problem, a much larger share than the roughly one in 10 who picked crime. About one in 15 said the biggest problem was the end of national abortion rights, following the Supreme Court's June decision that struck down a nationwide right to abortion.

The Reuters/Ipsos poll, conducted online in English throughout the United States, gathered responses from 1,004 adults, including 424 Democrats and 390 Republicans. It has a credibility interval - a measure of precision - of 4 percentage points either way.