(Repeats to additional clients with no change to text) April 15 (Reuters) - Treasury Secretary Janet Yellen’s first foreign exchange report due this week could see several U.S. trading partners labeled as currency manipulators. The designation is based on three broad criteria here A $20 billion-plus trade surplus with the United States, a current account surplus exceeding 2% of GDP and currency intervention exceeding 2% of gross domestic product. The criteria led the Trump administration to label Switzerland and Vietnam as currency manipulators in December. Whether Yellen takes as aggressive an approach as her predecessor in scolding trading partners is unclear. This time around, analysts say the following are at risk. SWITZERLAND * Switzerland was named by the U.S. Treasury as a currency manipulator in its December report after it met all three criteria. * For 2020, Switzerland ran a goods trade surplus of 28 billion Swiss francs with the U.S., according to data from the Swiss customs office. The United States is Switzerland’s second biggest trade partner after Germany. * The SNB currency interventions in 2020 were equivalent to 15.6% of Swiss GDP, far above the U.S. threshold of 2%. * The SNB appears to have reduced its interventions so far in 2021 as the franc has weakened, but Chairman Thomas Jordan said in March there was “absolutely no change in our monetary policy, so our willingness to intervene in foreign exchange market if necessary is exactly the same.” TAIWAN * Taiwan’s trade surplus with the United States hit $29.9 billion in 2020, according to official data, almost $7 billion more than in 2019, while the current account surplus last year was around 11% of GDP, exceeding Washington’s criterion. * The Taiwan dollar’s 5.6% gain against the greenback last year was among the strongest in Asia and it remains a strong outperformer this year. * The central bank said it intervened to the extent of $39.1 billion last year as it stepped up efforts in November and December to “avoid serious disorder”. * The island was last formally labelled a currency manipulator by the United States in December 1992. It was put back on the monitoring list in 2020. VIETNAM: * The U.S. trade deficit with Vietnam widened to $63.36 billion in 2020 from $46.90 billion in 2019, according to the Vietnamese government’s customs data. That deficit widened further in the March quarter. * The central bank bought a net $21 billion last year to increase its currency reserves to around $100 billion. U.S. Trade Representative Katherine Tai, in a call earlier this month with Vietnam’s minister of industry and trade, highlighted U.S. concerns about Vietnam’s currency practices. THAILAND: *The baht has come under pressure in recent months as a fresh coronavirus pandemic has scuppered the prospects of the tourism-reliant economy. It is likely to fall further in 2021 thanks to a much smaller current account surplus. *Thai officials have said they will take measures to ensure the currency will not impede an economic recovery. As of April 2, international reserves were $245.7 billion while net forward position stood at $33 billion. OTHER POSSIBILITIES: * The U.S. Treasury might change the threshold for the criteria used to determine if a country is manipulating its currency. The thresholds were last changed in May 2019 under the Trump administration making it easier for Washington to label countries as currency manipulators. * A number of countries are expected to remain or appear on the “monitoring list,” according to BBH’s Win Thin, among them China, Germany, Japan, Italy, India and Singapore. The yuan currency remains one of the strongest performers versus the greenback this year. ($1 = 0.8830 Swiss francs)