Japan will have little choice but to enter into a bilateral trade deal with the United States similar to one President Donald Trump clinched with South Korea, a former top currency diplomat from Japan said.

Naoyuki Shinohara, who was also deputy managing director at the International Monetary Fund, said Washington will keep pushing for a bilateral free trade agreement with Japan, given Trump's "America First" agenda — and Tokyo's calls to use a multilateral framework will only buy it some time.

"The United States is only interested in a bilateral deal and probably won't listen to Japanese calls for a multilateral approach on trade," said Shinohara, who remains in close contact with international financial diplomats.