A U.S. official said Washington is 'cautiously optimistic' about upcoming Russia-Ukraine peace talks in Abu Dhabi, saying there is an opportunity to make significant progress and that recent weeks have shown some flexibility from both sides on territorial issues. The official warned territorial agreements are unlikely before security guarantees are settled. The U.S. said European allies will play a key role in any post-war security arrangement and wants Russia to agree to include European repres

A U.S. official said Washington is 'cautiously optimistic' about upcoming Russia-Ukraine peace talks in Abu Dhabi, saying there is an opportunity to make significant progress and that recent weeks have shown some flexibility from both sides on territorial issues. The official warned territorial agreements are unlikely before security guarantees are settled. The U.S. said European allies will play a key role in any post-war security arrangement and wants Russia to agree to include European representatives in the next round of talks after Abu Dhabi.