South Korea said the U.S. had reaffirmed it would shoulder the cost of deploying the THAAD anti-missile system, days after President Donald Trump said Seoul should pay for the $1-billion battery designed to defend against North Korea.

In a telephone call on Sunday, Mr. Trump’s National Security Advisor, H.R. McMaster, reassured his South Korean counterpart, Kim Kwan-jin, that the U.S. alliance with South Korea was its top priority in the Asia-Pacific region, the South’s presidential office said. The conversation followed another North Korean missile test-launch on Saturday which Washington and Seoul said was unsuccessful, but which drew widespread international condemnation.

Mr. Trump, asked about his message to North Korea after the latest missile test, told reporters: “You’ll soon find out”, but did not elaborate on what the U.S. response would be.

Trump’s comments

Mr. Trump’s comments in an interview with Reuters on Thursday that he wanted Seoul to pay for the THAAD deployment perplexed South Koreans and raised questions about his commitment to the two countries’ alliance.

South Korean officials responded that the cost was for Washington to bear, under the bilateral agreement. “National Security Adviser H.R. McMaster explained that the recent statements by President Trump were made in a general context, in line with the U.S. public expectations on defence cost burden-sharing with allies,” South Korea’s Blue House said in a statement, adding that Mr. McMaster requested the call. About 300 residents rallied on Sunday as two U.S. Army lorries tried to enter the THAAD deployment site.