President Donald Trump’s approval rating has fallen to 33%, the lowest level of his presidency, as Americans grow increasingly concerned about the war with Iran and its economic impact, according to a Reuters/Ipsos poll released Monday.

The four-day survey found that 64% of respondents disapproved of Trump’s performance. His approval slipped from 35% in a Reuters/Ipsos poll completed earlier in August and matched the lowest level recorded during his first term.

Reuters reported that 80% of Americans believe the Iran conflict will continue for a long time, while only 20% said the war has been worth its costs. The conflict has disrupted oil shipments and contributed to higher gasoline prices, increasing pressure on household budgets.

The poll also found that Democrats have gained ground on economic issues and narrowed Republicans’ advantage on immigration as both parties prepare for the November midterm elections.