By Michael Hernandez

WASHINGTON 

President Donald Trump's national security strategy will prioritize the U.S. border and economic interests in an "unprecedented" way, a senior Trump administration official with knowledge of the forthcoming plan said Sunday.

"There is an unprecedented focus on homeland security and on the border," the official told reporters on condition of anonymity. "They were never mentioned in nearly as much detail and emphasis as they are now."

"The economic piece also gets much more attention, the insistence that economic security is national security," he added.

In addition to those two vital national security interests, the plan will also emphasize "preserving peace through strength", and "advancing American influence", according to a second senior administration official.

Trump will announce the Congressionally-mandated plan on Monday afternoon before it is formally posted.

It is expected to consider Russia and China as "revisionist powers", the Trump administration's phrase for those seeking a change to the global order's status quo.

"Russia's invasion of Ukraine, Georgia... those activities sought to change the status quo in Europe, and generally not a positive direction, nor a peaceful direction. Essentially that's what revisionism means," the second official, who was speaking under the same ground rules, said. "Also with China's building in the South China Sea they're trying to change the status quo, usually with military means to move trends in their favor."

The official said Beijing would be referred to as a "strategic competitor" because it competed effectively in the political, economic, informational and military spheres "in ways probably not duplicated by our other competitors".

Still, the official acknowledged that the U.S. did not rule out cooperation with China "in any way", and needed Beijing's help in halting North Korea's ballistic missile and nuclear programs.

In a major break from the Obama administration, Trump's security strategy will no longer consider climate change to be a national security threat.

The change was expected, but the official said climate and the environment "are discussed" in the new document.