South Korea's KOSPI fell sharply in early trade, slipping below 8,100 and down 1.63% on the day.

The International Energy Agency (IEA) said in a report that global investment in gas projects is expected to rise by more than 10% this year to $330 billion, a 10-year high, while upstream oil investment is set to fall for a third consecutive year. With the Iran war disrupting global energy markets, energy firms are accelerating investment in other regions and increasing spending on renewables, liquefied natural gas and coal to bolster supply security. In its 2026 Global Energy Investment Report, the IEA said that despite Middle East turmoil, energy-sector capital spending in 2026 is expected to grow 5% to $3.4 trillion, of which $2.2 trillion will be allocated to renewables, storage, grids and low-emission fuels. Oil-supply investment will be below $500 billion. Gas investment growth is driven mainly by U.S. LNG projects, but the current crisis has made Asian importers more cautious about reliance on gas. Coal investment will hit a 14-year high at $180 billion. Nuclear investment is recovering, with spending this year expected to reach $80 billion. The IEA expects Middle East oil-and-gas investment in 2026 to decline about 1%, citing infrastructure damage, revenue losses and production disruptions that have weakened capital-deployment capacity.

Iranian media on the 28th, citing a military source, said a few hours earlier a U.S. oil tanker attempted to transit the Strait of Hormuz with its radar turned off but was forced to stop and turn back after the Islamic Revolutionary Guard Corps Navy (IRGCN) acted swiftly and decisively and fired shots at it.