ZURICH, March 5 (Reuters) - Russia's invasion of Ukraine has introduced uncertainties as the global economy looks to move towards monetary policy normalisation, Swiss National Bank Governing Board Member Andrea Maechler told Swiss newspaper Schweiz am Wochenende.

"Globally, the need for monetary policy normalisation remains," Maechler said, pointing to a sharp rise in inflation in key markets like the United States and a rapidly recovering global economy. "To what extent this baseline scenario has now changed, and how strongly, is something we now need to examine," Maechler told the paper in an interview published on Saturday.

"It is difficult to say how long-term interest rates will develop. It depends, among other things, on how the Ukraine crisis will affect the global economy," she added.

Within Switzerland, it remained necessary to maintain negative rates.

"We have always said that we do not want negative interest rates. Things had been moving in a good direction. Only time will tell how much the overall picture will change now," she said.

"One thing is clear: As soon as we can lift the negative interest rate, we will do so. But in the current situation, it is still necessary for Switzerland."

The Swiss franc reached its highest value against the euro since 2015 on Friday, coming close to parity, as the war in Ukraine lowered expectations of European economic growth.

"There is a strong negative risk sentiment on the markets. In such phases, the focus shifts to the Swiss franc as a safe haven," Maechler said, adding the Swiss franc's appreciation had initially been moderate against rising geopolitical uncertainties. "That has now changed over the course of this week. Many questions remain open: about the course of the war, and about the implementation and consequences of sanctions."

WIDENING SANCTIONS

Maechler reiterated the SNB's willingness to intervene on foreign currency markets to stem the franc's safe haven rise.

In a sharp deviation from its traditional neutrality, Switzerland moved on Monday to adopt sanctions that the European Union (EU) imposed on Russian individuals and companies and freeze their assets to punish the invasion of Ukraine.

It widened sanctions against Russia on Friday, tightening exports and financial services to the country in step with further measures imposed by the European Union.

Less than 0.05% of the SNB's foreign currency reserves were tied to Russia, Maechler said, amounting to a "low three-digit million" amount in the SNB's massive portfolio.

"We are currently examining what to do with these assets while complying with sanctions," Maechler told the newspaper, adding the Swiss National Bank did not hold any shares in Russian companies or in ruble-denominated bonds.

"Indirectly, the SNB is certainly affected by the changes in the global commodity and energy markets. In terms of monetary policy, the SNB is feeling the greatest effects of the Ukraine war indirectly, via financial markets and then via the economic effects linked to them," she said.

The SNB still expected global inflation to normalise in the medium term despite a rise in commodity and food prices.

An increase in long-term interest rates since the start of 2022 had begun to slow, particularly in Europe, against the backdrop of the Ukraine conflict, Maechler noted.

Asked about the possibility of a merger between the country's two biggest banks on the back of recent scandals at Switzerland's No. 2 bank, Credit Suisse, Maechler said a potential tie-up with UBS could cause concentration risks.

"Both big banks are systemically important. If there were only one big bank, the risks would be concentrated in a single institution. That would not be good from an overarching perspective," she said. (Reporting by Brenna Hughes Neghaiwi;)