Oil prices rose slightly on Tuesday due to worries about supply issues in Iran, which were stronger than hopes for more oil coming from Venezuela. Brent crude futures increased by 28 cents, or 0.4 percent, reaching $64.15 a barrel by 0101 GMT, close to a two-month peak from the day before. U.S. West Texas Intermediate crude also went up by 28 cents, or 0.5 percent, hitting $59.78, its highest level since December 8 earlier in the day. Iran, a leading member of the Organization of the Petroleum Exporting Countries, is experiencing its largest anti-government protests in years. This situation has led U.S. President Donald Trump to warn of possible military action in response to the violence against protesters. A U.S. official told Reuters that Trump plans to meet with senior advisers on Tuesday to consider options regarding Iran. On Monday, Trump declared that any country trading with Iran would face a 25 percent tariff on business with the United States. These events are significant for oil markets because Iran is a heavily sanctioned oil producer, and any increase in tensions could disrupt supply and raise geopolitical risks. Barclays noted that unrest in Iran has likely added about $3 to $4 per barrel in geopolitical risk premium to oil prices. Additionally, markets are concerned about more crude supply potentially flooding the market due to Venezuela's expected return to oil exports. After the removal of President Nicolas Maduro, Trump stated last week that the Caracas government might transfer up to 50 million barrels of oil, albeit under Western sanctions, to the U.S.