"The SNB conducts an in-depth monetary policy assessment in March, June, September and December. Its monetary policy decision is based on this assessment," it said in The Swiss National Bank in Brief https://www.snb.ch/en/mmr/reference/kurzportraet/source/kurzportraet.en.pdf publication that describes its mandate.

"In addition, the SNB may take monetary policy measures at any time between regular assessment dates if circumstances so require," it added.

In June, the SNB raised its policy interest rate for the first time in 15 years in a surprise move and said it was ready to hike further, joining other central banks in tightening monetary policy to fight resurgent inflation.

In its publication on Thursday, the SNB also reiterated its position that it may purchase or sell foreign currency against Swiss francs on the financial markets in order to fulfil its monetary policy mandate.

June's rate rise was the first by the SNB since September 2007. Other central banks are also raising rates as they attempt to cool inflation driven higher by surging fuel and food prices that are straining budgets for households and businesses.

The Federal Reserve said on Wednesday it would not flinch in its battle against the most intense breakout of inflation in the United States since the 1980s even if that means a "sustained period" of economic weakness and a slowing jobs market.

(Reporting by Paul Carrel, Editing by Miranda Murray and Michael Shields)