OPEC, Russia and other producers are in the midst of a joint effort to force a rebalancing of the oil market, with prices climbing to two-and-a-half-year highs in recent weeks.

However, with persistently strong oil exports dampening market sentiment and capping gains, CNBC takes a look at the world's 10 leading oil exporters.

Angola exported 1.7 million barrels per day (mb/d) in 2016, according to data published by The Organization of the Petroleum Exporting Countries (OPEC).

Oil production and its supporting activities contribute to approximately 45 percent of Angola's gross domestic product (GDP) and around 95 percent of its exports.

Since joining OPEC in 2007, Angola has become the cartel's sixth largest oil exporter.

Nigeria, the most populous country within OPEC, is Africa's largest oil exporter and producer.

In 2016, the country narrowly beat Angola to export just over 1.7 mb/d, according to data published by OPEC.

Venezuela, a founding member of the now 14-member cartel, exported around 1.9 mb/d in 2016, according to OPEC.

While the South American country boasts the largest oil reserves in the world, it is currently in the midst of a full-blown crisis. The ongoing turmoil was sparked by years of economic mismanagement exacerbated by a three-year downturn in oil prices. Venezuela has suffered food shortages, runaway inflation and violent street clashes, as President Nicolas Maduro has prioritized paying international creditors.

Oil revenues account for approximately 95 percent of the country's export earnings.

Iran exported almost 2 mb/d in 2016, according to data published by OPEC.

President Donald Trump has threatened to terminate an international nuclear pact with Iran and if the U.S. Congress agrees, Tehran could be placed under renewed sanctions, affecting international companies' ability to do business in and with the oil-rich country.

Kuwait exported more than 2.1 mb/d in 2016, according to OPEC estimates.

The OPEC member's oil and gas sector accounts for around 60 percent of the country's GDP as well as 95 percent of its export revenues.

The United Arab Emirates exported almost 2.5 mb/d in 2016, according to OPEC data.

Approximately 40 percent of the country's GDP is directly based on oil and gas output. The country, which consists of seven emirates along the Arabian peninsula, joined OPEC in 1967.

Canada exports just over 3.2 mb/d, according to the most recent data published by the World Factbook.

The non-OPEC member exported almost as much as Africa's two leading exporters combined. Canada has the world's third-largest oil reserves.

OPEC and Russian officials have called on some of the world's leading oil producers, both inside and outside the cartel, to form a consensus and back a supply curb until the end of 2018.

And while Iraq is OPEC's second-biggest producer and exporter of oil, Baghdad has yet to drive down output to levels it agreed to last winter.

Iraq exported 3.8 mb/d in 2016, according to data published by OPEC.

Russia, the world's largest oil exporter outside of the oil-producing cartel, pumped more than 5.1 mb/d, according to the most recent data published by the World Factbook.

Moscow and its OPEC rivals have been seeking to curtail oil output to clear a global supply overhang since January. The goal is to shrink global crude stockpiles and drain a glut that has weighed on prices for the last three years.

Saudi Arabia is the world's leading exporter and second largest producer of oil. The OPEC kingpin exported 7.5 mb/d in 2016, according to data published on the cartel's website.

The Kingdom's heir to the throne ordered the arrest of powerful royals and businessmen at the start of November, in what officials called an anti-corruption drive but outside observers deemed to be a domestic power consolidation.

Some believe the extraordinary purge is an attempt by Mohammed bin Salman to consolidate his power by eliminating potential rivals. And that may herald political uncertainty, tension and possibly unrest not seen before in the history of OPEC's biggest oil producer.