While "there is a lot of positive news for the recent move higher in oil", said Scott Gecas, senior strategic account executive at Long Leaf Trading Group, "the biggest factor to me is last week's inventory report, [which] showed a huge 4.6 million barrel decline" in US crude stocks.
Oil hit US$70 a barrel today, in its biggest two-day rally in almost a month, as investors grew more confident that a brewing trade dispute between the United States and China may be resolved without causing harm to the global economy.
Brent, the global benchmark, gained $1.35, or 2%, to $70.00 a barrel.
U.S. West Texas Intermediate crude for May delivery was up 19 cents, or 0.3 percent, at $63.56 a barrel by 0140 GMT after settling down 14 cents.
The gains followed a more than 2 percent rally on Monday during European and American trade hours, but that was a rebound from a 2 percent decline on Friday.
-China trade tensions and rising geopolitical upheaval in the Middle East.
Yet prices remain within recent ranges as oil markets still face an abundance of supply that puts pressure on producers to keep their prices competitive in order not to lose market share.
Analysts said Xi's comments greatly relieved market anxiety for a potential trade war between the world's two largest economies.
Investors looked forward to data on USA crude inventories and Organisation of Petroleum Exporting Countries (OPEC) production levels.
Also supportive to crude prices was the weakness of the USA dollar.
There are also concerns that the United States could renew sanctions against Iran, a major Middle East oil producer.
In other energy news Tuesday, the U.S. Energy Information Administration raised its 2018 and 2019 price forecasts for WTI and Brent crude.
Oil prices are still showing a gain so far this year, thanks to healthy demand and by supply restraint led by the Organization of the Petroleum Exporting Countries, which started in 2017 to rein in oversupply and prop up prices.
However, soaring USA crude production, which has jumped by a quarter since mid-2016 to 10.46 million barrels per day (bpd), is threatening to undermine OPEC's efforts to tighten the market and prop up prices.
OPEC and other producers, including Russian Federation, agreed to cut output by about 1.8 million barrels per day (bpd) in November last year to slash global inventories to the five year-average.