OIL prices are set to slip again, in the wake of a key weekend meeting on output volumes - a development that could move markets at the re-open on Monday.

The Organization of the Petroleum Exporting Countries (Opec) has announced that it would raise production, but did not say by how much or from where. Saudi Arabia is reportedly flexing its muscles in the group to find a price ceiling that will please producers and traders alike.

But the oil production debate among cartel members has played second fiddle in the headlines to United States President Donald Trump's wide-ranging trade skirmishes with everyone from neighbouring Mexico to faraway China, a key target of his ire.