Story highlights Trump also requested an additional $700 million to repair damage to US Navy ships

Earlier this year, the Trump administration requested a $54 billion defense budget increase

Washington (CNN) President Donald Trump has asked Congress to approve an additional $6 billion in defense spending for fiscal year 2018 -- including $4 billion "to support urgent missile defeat and defense enhancements to counter the threat from North Korea."

In a letter to House Speaker Paul Ryan, Trump also requested an additional $700 million to repair damage to US Navy ships and $1.2 billion in support of the administration's South Asia strategy.

"This request supports additional efforts to detect, defeat, and defend against any North Korean use of ballistic missiles against the United States, its deployed forces, allies, or partners," the letter said.

An additional $700 million would be used to "repair damage to and restore the operational readiness of the USS John S. McCain and the USS Fitzgerald," according to the letter.

"These ships provide critical naval presence and additional ballistic missile defense capabilities in the Asia-Pacific theater," the letter said.

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