While responding to questions about Seoul's decision to suspend THAAD's deployment pending an environmental assessment, Nauert said, "Those were parts of the conversations that he (Tillerson) had today with Secretary Mattis, and also at the White House."

Seoul's presidential office, Cheong Wa Dae, said Wednesday that deployment of four launchers for the THAAD battery should wait until the environmental study is over, though two, already-deployed launchers won't be withdrawn, a decision that the US could see as a setback to its efforts to fully deploy the system as soon as possible.

Nauert said that North Korea's latest missile launches, conducted earlier Thursday, show that THAAD is "something that's important to, not only to protect US forces, to protect our alliance and to protect -- help to further strengthen the region."

"We are committed to our South Korean ally. That commitment remains ironclad. We are aware, certainly, of the situation and the suspension of additional launchers," she said. "We would continue to say that THAAD was an alliance decision at the time, and we continue to work closely with the ROK throughout their process." (Yonhap)