The FTSE 100 gained 0.1 percent and the FTSE 250  added 0.3 percent by 0848 GMT on the final trading day of 2018, continuing Friday's rally when they both closed over 2 percent higher.

Trump said on Twitter that he had a "long and very good call" with Chinese President Xi Jinping and that a possible trade deal between was progressing well.

In a shortened session on account of new year's eve, UK's main index was lifted by gains in mining stocks as copper prices rose on signs of progress in U.S.-China trade talks.

Glencore, Rio Tinto, Anglo American and BHP advanced roughly by 1 percent.

But a stronger sterling pulled down exporter stocks with Reckitt Benckiser, GlaxoSmithKline, Unilever  all falling 0.6-1.2 percent.

The mid-cap index, which makes roughly 70 percent of its income abroad, was carried higher by gains in consumer and industrial shares.

The gains come just a couple of sessions after the index flirted with bear market territory, closing just shy of the required 20-percent-drop.

Both indexes are on track for their biggest yearly losses since the 2008 financial crisis, dragged down by fears over the U.S.-China trade war, Brexit uncertainties and the more recent government shutdown in the world's largest economy.

The FTSE 100 has slumped 12.4 percent since the start of 2018 and the FTSE 250, which is more exposed to Brexit outcomes, has tanked 15.7 percent over the same period.

AIM-listed oil and gas company Cabot Energy tumbled 37 percent to hit a life low after saying an absence of a fundraising next month would cast significant doubt upon its going concern abilities.