The Swiss National Bank (SNB) has said it is prepared to intervene in currency markets if it deems that the Swiss franc has gained too much strength.

The central bank kept its main borrowing rate in negative territory Thursday as it acknowledged the risks of global trade friction and political change in Italy.

Since April, the Swiss franc has appreciated about 5 percent against the euro, creating a drag on the export-led Swiss economy.

SNB President Thomas Jordan told CNBC on Thursday that every time there was uncertainty in Europe, there was renewed interest in the safe-haven franc.

“We have the case in Italy that had a big impact on international financial markets and we can also see that the euro has become weaker. So we see more risk, especially in Europe. But we also see more risk from those international trade issues,” he said.

Jordan said he could not outline a timetable for any attempt to weaken the Swiss currency, but policymakers stood ready to take action.

“It is very important that we continue our expansionist monetary policy. So we have the negative interest rates of minus 75 basis points, but also our willingness to intervene in foreign exchange markets if necessary,” he added.

In April, the Swiss franc briefly weakened past 1.20 per euro for the first time since the SNB abruptly removed its cap on the currency in 2015. The Swissie has quickly strengthened since mid–April and now stands at about 1.15 to each euro.