According to strategists at Commerzbank AG, even the disapproval of the U.S. government may not be enough to prevent the Swiss National Bank from intervening in the currency market.

The Swiss franc reached its highest level since April 2017 against the euro after Washington added Switzerland back to its currency watch list and urged the country to adjust its macroeconomic policies.

Yet strategists say Switzerland's growth and inflation data could make the case for the SNB to continue buying foreign currency in an effort to curtail the franc's appreciation.

"We know from the SNB's intervention activity that the franc is already at critical levels, i.e. at levels at which it has intervened before last year. There is a high likelihood that it will step into the market, or is already active." said Thu Lan Nguyen, a strategist at Commerzbank

SNB data in August suggested the bank had pumped billions of francs into markets, buying foreign currency in an effort to curb the franc's strength. The SNB said Tuesday that its interventions were designed only to offset the ill effects of too strong a currency. The interventions, which aren't aimed at giving the nation a competitive advantage, are disclosed in an annual report, the SNB said in a statement.