Denmark’s foreign minister said on Thursday he was “more optimistic” after the first senior-level talks with the United States over Greenland. 

“We have had the very first meeting at senior official level regarding the Greenlandic issue,” Lars Løkke Rasmussen told journalists at an EU meeting in Brussels. “It went well in a very constructive atmosphere and tone, and new meetings are planned. It’s not that things are solved, but it’s good.”

Trump’s earlier threats to take control of Greenland caused tensions in the transatlantic alliance. Rasmussen said the situation had escalated but is now “back on track,” adding he felt “slightly more optimistic today than a week ago.”

Although a “framework” deal with NATO chief Mark Rutte was announced, few concrete details have been disclosed. Authorities in Denmark and Greenland have consistently refused to discuss ceding sovereignty. “We, of course, share the U.S. security concerns regarding the Arctic, and this is something we want to solve in close cooperation,” Rasmussen said.

As part of the ongoing talks, NATO is expected to strengthen its activities in the Arctic. Denmark and Greenland may also renegotiate the 1951 treaty governing U.S. troop deployments.