US President Donald Trump and Japanese Prime Minister Shinzo Abe noted the importance of trilateral cooperation with South Korea during their talks in New York Wednesday, the White House said.

In their meeting on the sidelines of the United Nations General Assembly, Trump and Abe discussed issues of mutual interest and signed a preliminary bilateral trade agreement.

The White House did not elaborate on the discussions on South Korea, but the two leaders are likely to have touched on the escalating tensions between Seoul and Tokyo over trade and wartime history disputes.

"President Trump and Prime Minister Abe also noted the importance of trilateral security cooperation between the United States, Japan, and the Republic of Korea," it said in a readout.

The US fears the tensions between its two East Asian allies could hurt trilateral security cooperation against North Korea's nuclear threats and China's military rise.

Washington voiced disappointment and concern after South Korea decided last month to withdraw from a military intelligence-sharing pact with Japan.

In July, Trump said of South Korea and Japan, "If they need me, I'm there."

Trump and Abe also discussed "affairs with respect to Iran and the Democratic People's Republic of Korea," the White House said, referring to North Korea. (Yonhap)