As the Group of Twenty (G20) summit in Argentina draws closer, International Monetary Fund (IMF) chief Christine Lagarde on Wednesday called for swift joint actions to reduce trade barriers and improve global trade system.

In a blog post published on IMF's website, Lagarde said rising trade barriers are ultimately "self-defeating" for all involved. "It is imperative that all countries steer clear of new trade barriers while reversing recent tariffs."

In a surveillance note prepared for the upcoming G20 summit, the IMF also stressed that there is "an urgent need" to de-escalate trade tensions and to modernize the global trading system.

The IMF's World Economic Outlook released in October had forecasted global growth of 3.7 percent for 2018 and 2019, down by 0.2 percentage points from its July estimates, largely due to rising external and financial pressures on emerging markets and a "tangible" increase in trade tensions, the IMF managing director said.

Citing data from an IMF research, Lagarde noted that liberalizing trade in services could, in the long run, add about 0.5 percent, or 350 billion U.S. dollars, to the gross domestic product (GDP) of the G20, the world's top 20 economies.

Besides tackling trade issues, renewed multilateral cooperation is also needed to bring down external imbalances, avoid rollback of post-crisis advances in financial sector regulation, coordinate support for low-income countries, and address other global challenges such as climate risks, and international taxation, the IMF said in its surveillance note.

Pointing out that the progress toward the G20 goals of more balanced, sustainable and inclusive growth "remains slow," the multilateral lender encouraged policies to help narrow excess external imbalances, keep domestic vulnerabilities in check, jointly undertake structural reforms, and invest in human capital in combination with strong social safety nets, appropriate fiscal redistribution and access to health care.

Highlighting the "darker clouds" that are looming over the global economy, Lagarde said tackling this challenge means implementing policies that make sense both nationally and internationally. "Teamwork is the winning tactic," she said.