While the summit is unlikely to produce a formal security arrangement that commits the nations to each others' defense, they will agree to mutual understanding about regional responsibilities and set up a three-way hot line to communicate in times of crisis, the officials said. The officials spoke on condition of anonymity.

U.S. President Joe Biden invited his counterparts, Japanese Prime Minister Fumio Kishida and South Korean President Yoon Suk Yeol, to the storied presidential in Maryland's Catoctin Mountains as the nations work to mend tattered diplomatic relations in the face of greater regional threats posed by China's rise.

"We are anticipating some steps that will bring us closer together in the security realm," said one of the U.S. officials, and that doing so would "add to our collective security."

But the U.S. official added that, "it's too much to ask - it's a bridge too far - to fully expect a three-way security framework among each of us. However, we are taking steps whereby each of the countries understand responsibilities with respect to regional security, and we are advancing new areas of coordination and ballistic missile defense, again technology, that will be perceived as very substantial."

The summit is also expected to lead to a joint statement between the countries that includes some language speaking to concerns about China's attempts to change the status of self-governed Taiwan, which it claims as its own territory.

The U.S., Japanese and South Korean joint statement is set to include language on maintaining peace and stability in the Taiwan Strait, one of the officials said. The exact language is expected to be negotiated up to the last minute.

Such language would be consistent with prior U.S. positions on the subject, avoiding escalation with Beijing as Washington has been seeking to ease tensions.