Global sovereign bonds rallied overnight. The 10-year Treasury note yield plunged to 1.939%, a level last seen following Donald Trump's election as president in November 2016.
Malaysia relies on palm oil - a commodity used in everything from chocolate spread to lipstick - for billions of dollars in foreign exchange earnings and hundreds of thousands of jobs.
A tired-looking Lam appeared in public for the first time in nearly two weeks to attend the anniversary ceremony, flanked by her husband and former Hong Kong leader Tung Chee-hwa.
Analysts doubt the truce will lead to a sustained easing of tensions while lingering uncertainty could dampen corporate spending appetite and global growth.
The world's two largest economies are in the midst of a bitter trade war, which has seen them level increasingly severe tariffs on each other's imports.
Trump declined to respond to reporters' questions on whether he would address the death last year of Saudi journalist Jamal Khashoggi, a critic of MbS.
Michael McFaul, former U.S. ambassador to Russia under Trump's Democratic predecessor, Barack Obama, said Trump's deference to Putin was "disappointing but no longer shocking."
Uncertainty over whether the talks will produce progress in ending the year-long trade war between the world's two largest economies comes amid signs of rising risks to global growth.
Trump, who is holding a series of meetings on the sidelines with world leaders, including Japan's Shinzo Abe and India's Narendra Modi, said he saw U.S. trade prospects improving.
The MAS will wait for second quarter growth numbers in July before finalizing any revision to its full-year forecast, said Ed Robinson, deputy managing director for economic policy.