(Reuters) - A Donald Trump presidency could be net bearish for oil prices due to a combination of factors including tariffs and oil-friendly policies, and pushing the Organization of the Petroleum Exporting Countries and allies (OPEC+) to release more oil into the market, Citi said in a research note on Thursday.

"Trump could roll back environmental policies, though broadly overturning the (Inflation Reduction Act) looks unlikely due to its positive impacts in red states," analysts noted, referring to states that are Republican leaning.

The main bullish risk for oil markets under a Trump presidency would be would be pressure on Iran, they added, though this could have a limited impact. If Trump were to readopt a "maximum pressure" campaign on Iran, the market could see a 500-900 thousand barrel per day impact on Iranian oil exports.

U.S. President Joe Biden abandoned his reelection bid on Sunday and endorsed Vice President Kamala Harris as the party's candidate for the November election, following growing pressure from his fellow Democrats.

"A Harris administration may be similar to, or slightly left of Biden," Citi analysts said.

Meanwhile, the market continues to face geopolitical, cyber and weather-related risks.

"Hurricane season is far from over - Mideast tensions remain high, with fighting in Gaza, the West Bank, Lebanon, Syria, and Yemen. However, pressure has also been mounting for a push for a ceasefire, which could conceivably be forthcoming this summer," Citi added.