EVIA, Greece (Reuters) -Uncertainty over tariffs will not stall Holcim's plans to expand into the United States, the chief executive officer of the Swiss building materials supplier said on Thursday. 

A Manhattan-based court ruled on Wednesday that U.S. President Donald Trump overstepped his authority by imposing across-the-board duties on imports from trading partners. The news was met with cheers from markets but also creates uncertainty about how the situation will play out for companies.

This month, Holcim received shareholder approval to spin off the cement maker's North American business, Amrize, to enable greater focus and benefits from increased construction spending in the United States.

"We produce locally and we sell to local customers. So the impact from the tariffs for us is non-existent," Chief Executive Miljan Gutovic told Reuters in Greece at the opening of a 400-million-euro ($454 million) net-zero cement plant. 

The spin-off of its U.S. business will take place by the end of June as planned, he said.

"I think (it will happen) any day now, probably in the second half of June," Gutovic said.  

($1 = 0.8816 euros)