ICE cotton futures climbed more than 2% to a six-month high on Thursday, bolstered by positive comments from the US President Donald Trump on trade negotiations with China, while a firmer export sales data further supported market sentiment.

Cotton contracts for March rose 1.01 cent, or 1.5%, to 66.89 cents per lb by 12:40 p.m. ET (1740 GMT). It rose to 67.38 cents per lb earlier in the session, a level last seen on June 13.

"Export sales came out and they weren't bad, plus there are hopes that we're going get something done on (US-China) trade... There is a lot of optimism in the market," said Sid Love, commodity trading adviser at Kansas-based Sid Love Consulting.

The US Department of Agriculture (USDA) in its weekly export-sales report showed net sales of 277,100 running bales (RB) for the 2019/20 marketing year, up 69% from the previous week and 9% from the prior four-week average, for the period ended Dec. 5.

Adding to the upbeat mood, Trump said Washington was "very close" to nailing down a trade deal with China, just days before new US tariffs on Chinese imports were due to be imposed. The United States is one of the world's biggest producers of the natural fiber, while China is the largest consumer.

Optimism around the trade negotiations has lifted cotton prices nearly 20% since touching a more than three-year low in late August.

On the technical front, "ICE futures should experience resistance near 67.50-68 cents and then 69 cents and 70-71 cents basis March over the near to medium term," said Louis Rose, director of research and analytics at Tennessee-based Rose Commodity Group in a note.

Total futures market volume rose by 16,791 to 35,652 lots. Data showed total open interest gained 201 to 195,064 contracts in the previous session. Certificated cotton stocks deliverable as of Dec. 11 totaled 27,057 480-lb bales, down from 34,090 in the previous session.