The South Korean won strengthened to around 1,360 per dollar, recovering from four-week lows as a sharp decline in oil prices reduced demand for the dollar. WTI crude fell 4.5% to below $100 a barrel, while Brent declined more than 3% amid hopes for progress in US-Iran diplomacy and the recovery of Saudi oil shipments. The US 10-year Treasury yield also slipped below 5% after reaching recent highs last week, further easing support for the dollar. South Korea's exports rose 78% year-on-year during the first 20 days of September, led by a 259% increase in semiconductor shipments that helped boost dollar inflows. The dollar nevertheless remained relatively firm as markets assessed the possibility of another Federal Reserve rate increase later this year. The Bank of Korea said it would consider inflation, growth and financial stability when deciding the timing and pace of further rate hikes.