US Gulf Coast medium sour crude Mars rose to its highest assessed level in almost two years Monday on market anticipation of possible Venezuela crude sanctions, continued export demand and an OPEC meeting to discuss production cut compliance. S&P Global Platts' Mars assessment increased 10 cents/b day on day to WTI cash minus 45 cents/b, its highest level since August 31, 2015, when it reached minus 35 cents/b. The strength coincided with an OPEC meeting Monday to discuss stricter compliance with its production cut deal with 10 non-OPEC producers, as total output reached about 920,000 b/d above its normal ceiling of around 31.9 million b/d. Increasing output from Libya and Nigeria, both of which were exempt from compliance with cuts, has contributed to the rise in production. However, much of the crude produced by Nigeria is sweet, meaning any further production cuts on the part of OPEC members could serve to tighten an already stretched global sour crude market, according to a source. The increase in the Mars differential also coincided with anticipation of possible US sanctions on Venezuela crude imports, according to the source. Any restrictions placed on US imports of Venezuelan crude would mean domestic refiners would have to look to the Middle East to find pricier replacement barrels. This has added to support for Mars despite its quality differences with heavy sour Venezuelan grades. A narrowing spread between USGC grade LOOP Sour and second-month Dubai, the benchmark for Middle Eastern crudes delivered to Asia, has made USGC exports to Asia less economic. As a result, US crude exports to Asia fell 28,000 b/d month on month in June to 212,000 b/d. Despite the decrease, these export volumes remain well above the 2016 average of 54,000 b/d. Continued, albeit somewhat damper, demand from Asia has added to support for USGC medium sour crudes, with cargoes of Mars, Southern Green Canyon and Poseidon heading to South Korea and India most recently.