NEW YORK -- U.S. President Donald Trump blasted India and Vietnam for their trade practices ahead of his arrival at the Group of 20 summit, targeting the Asian countries as the Sino-American trade war drags on.

"I look forward to speaking with Prime Minister [Narendra] Modi about the fact that India, for years having put very high tariffs against the United States, just recently increased the tariffs even further," Trump tweeted hours before landing in Osaka on Thursday local time. "This is unacceptable and the tariffs must be withdrawn!"

Trump called Vietnam "almost the single worst abuser of everybody" in a Fox Business Network interview Wednesday. "A lot of companies are moving to Vietnam, but Vietnam takes advantage of us even worse than China," he said.

Asked whether he wanted to impose tariffs on Vietnam, Trump said that "we're in discussions with Vietnam."

Trump's remarks suggest that he sees America's trading partners in Asia -- allies or otherwise -- as potential targets of trade actions even as Washington remains locked in a tit-for-tat tariff war with Beijing that has sent shock waves through global supply chains.

The Indian tariffs Trump referred to were imposed on 28 American products this month after India lost its so-called Generalized System of Preferences trade privilege, which waived duties on around 7% of total U.S. imports from India in 2017.

Indonesia's and Thailand's qualification for the GSP benefit also came under review last year. Indonesia's commercial attache in Washington told the Nikkei Asian Review this month that the country is still working to maintain its status.

Trump's criticism of Vietnam came amid a trend of companies shifting production there from China to skirt American tariffs. Companies also appear to be rerouting Chinese exports to the U.S. via Vietnam, a Nikkei analysis has found.

Members of the Association of Southeast Asian Nations are increasingly caught in the crossfire of Trump's broadening trade war, according to Maybank. The Trump administration may label a country a currency manipulator and make such threats as the removal of trade privileges "to extract trade concessions, influence ASEAN's trade relationships with China, or possibly pressure the country to take sides" in the conflict, analysts at the Malaysia-based investment bank wrote in a research note this month.

"ASEAN is staying neutral in the U.S.-China tech war ... but may face increasing pressure and collateral damage given the widening reach of U.S. export controls on emerging and foundational technologies," the report said.