Oil prices showed optimism on Friday, after Saudi Arabia said output cuts led by the Organization of the Petroleum Exporting Countries (OPEC) and Russia should be extended into 2019 to tighten the market.

Following the announcement, international benchmark Brent futures for May delivery gained 0.06 percent to $68.91 per barrel, while crude West Texas Intermediate (WTI) added 0.2 percent to $64.44.

Brent was on track for a 5 percent increase for the week, which is its strongest since July 2017, while WTI rose to about 4.2 percent.