WASHINGTON (Reuters) - The U.S. Treasury Department is unlikely to release its long-delayed semi-annual report to Congress on international currency manipulation until after the U.S. presidential election on Nov. 3, a source familiar with the matter said on Friday. The report was due in April, but its release has slipped repeatedly, initially due to the COVID-19 crisis and more recently given U.S. Treasury Secretary Steven Mnuchin’s focus on domestic fiscal stimulus negotiations. The last report released by Treasury in January reversed the department’s designation in August 2019 of China as a currency manipulator. It included nine countries - Germany, Ireland, Italy, Japan, Malaysia, Singapore, South Korea, Vietnam and Switzerland - on its watchlist. The U.S. Trade Representative’s office earlier this month opened an investigation into whether Vietnam has been undervaluing its currency and harming U.S. commerce, a charge that Vietnamese officials denied. Vietnam has been on the U.S. watchlist given its trade surplus with the United States, a large current-account surplus and a perception that its central bank has been actively buying foreign currency. The U.S. Treasury in August found that Vietnam’s currency was undervalued in 2019 by about 4.7% against the dollar due in part to government intervention. Switzerland is at risk of being branded as a currency manipulator due to interventions by its central bank to curb the appreciation of the franc. Thailand and Taiwan have also sparked concerns, said Mark Sobel, a former Treasury official who is now U.S. chairman for the Official Monetary and Financial Institutions Forum think tank. He said there was a long history of Treasury missing deadlines for the reports under both Democratic and Republican administrations. “It makes sense not to issue the report amid the heat of the elections and when Secretary Mnuchin is busy negotiating possible stimulus measures. He has bigger fish to fry,” Sobel said.