South African President Cyril Ramaphosa criticized U.S. President Donald Trump’s decision to boycott the upcoming G20 summit in Johannesburg, calling it “their loss.”

Ramaphosa said Wednesday that Washington’s absence would not affect the summit’s success and urged the U.S. to reconsider the effectiveness of “boycott politics.”

“It is unfortunate that the United States decided not to attend the G20,” Ramaphosa told reporters in Cape Town. “The meeting will go on, and important decisions will be made. Their absence is their loss.”

Trump announced last week that no U.S. officials would attend the Nov. 22–23 summit, citing his disputed claims that white South Africans face violent persecution and illegal land seizures.

The G20 gathering — the first ever hosted in Africa — will bring together leaders from the world’s largest economies, including China, Russia, India, Japan, and the European Union. The U.S. is set to assume the group’s rotating presidency at the end of the year.

Ramaphosa said the boycott undermines America’s role as “the world’s largest economy” and a key player in global decision-making.

Trump had previously clashed with Ramaphosa over the same allegations during a White House meeting in May, where the South African leader had encouraged him to attend the summit.

Relations between Washington and Pretoria have deteriorated in recent months over South Africa’s criticism of Israel and its genocide case against the country at the U.N.’s top court.

U.S. Secretary of State Marco Rubio had earlier skipped a G20 foreign ministers’ meeting in South Africa, describing Pretoria’s policies as “anti-American.”