Details on the maneuvers, involving two U. S. aircraft carriers and Japanese warships, were disclosed as Defense Secretary Jim Mattis arrived in Singapore for a conference.
SINGAPORE — United States officials said on Friday that naval maneuvers this week off the Korean Peninsula were the first in two decades to involve two American aircraft carriers in those waters and were intended as a “message of reassurance” to the region.
The new details about the exercises, which also involved Japanese warships, were disclosed as Defense Secretary Jim Mattis arrived in Singapore for a security conference during which concerns over North Korea’s nuclear and missile programs are certain to be front and center.
“This is about readiness, ” said David F. Helvey, a senior adviser on Asian security issues to Mr. Mattis. “This demonstrates that the United States has military capabilities across the western Pacific, including in the Sea of Japan.”
He added: “It sends a message of reassurance, and it does send a message of resolve. But this is part of our routine actions and our presence.”
The defense secretary is also seeking to shore up relations with allies made nervous by President Trump’s campaign talk about pulling back American security commitments in the region.
Mr. Mattis declined to discuss security issues on the record with reporters who traveled on his plane from Washington. But he read a short statement outlining themes he planned to address in a speech on Saturday, including the importance of “strengthening alliances, ” “upholding international law” and “maintaining stability.”
“As a Pacific nation, we have enduring interests and commitments in the Asia-Pacific region, ” said Mr. Mattis, noting the need to help nations bolster their own security while strengthening the United States military to deter war.
