Crude futures traded on a mixed note Tuesday, with U.S. prices moving lower and global prices on the rise as traders tracked developments in the Russia-Ukraine war that look to raise the risk of oil-supply disruptions from one of the world’s largest producers.

The U.S. dollar was also up on Tuesday at nearly its highest level in a year, while another persistent oil production outage at the Tengiz oilfield in Kazakhstan has resulted in a 30% decline in production for the field while repairs are completed.

Oil prices edged up on Monday after fighting between Russia and Ukraine intensified over the weekend, although concerns about fuel demand in China and forecasts of a global oil surplus weighed on markets.