(CNN) -- U.S. President Barack Obama arrived in South Korea on Wednesday, where the leaders of top global economies will convene at the G-20 summit to try to stabilize the world's financial markets.
Obama left Indonesia hours early, because volcanic ash from Mount Merapi could have grounded Air Force One, administration officials said.
The president's visit to Seoul will include a meeting with South Korean President Lee Myung-bak and a meeting with Chinese President Hu Jintao.
Obama is also scheduled to deliver a speech to U.S. troops in South Korea on Thursday, the Veterans Day holiday in the United States.
Tensions about currency and trade are likely to run high at the G-20 meeting, which will be held Thursday and Friday in Seoul, the South Korean capital.
Officials in China and the United States have accused the other of manipulating its currency at the expense of other economies. And the G-20 has acknowledged that the global economic recovery is advancing in "a fragile and uneven way".
Widespread protests are expected at the summit, for which South Korea has mobilized its largest security force ever, according to the Yonhap news agency. A total of 50,000 police and riot police are being deployed, authorities told Yonhap.
CNN
