White House domestic policy chief calls California 'occupied territory'

"Just landed in California. POTUS power swing through occupied territory," Joe Grogan, director of the Domestic Policy Council, tweeted Tuesday night.

Grogan's comments come just as Trump landed on the West Coast, where he's expected to visit several western states including California -- home to a few Republican enclaves, but historically a secure Democratic heavyweight. Occupied territory typically refers to land that has been conquered by an opposing force, such as another country's military.

CNN has reached out to the White House and to California Gov. Gavin Newsom's office for comment on Grogan's tweet.

Trump is heading to the Golden State this week for a combination of political and official engagements -- and to counter-program his potential Democratic rivals as they convene in Nevada.

The tweet is representative of Trump's ongoing clashes with California. The President has bashed the state before for its immigration and environmental policies. He lost the state to his 2016 Democratic rival Hillary Clinton by a wide margin, for which he blames the loss on unfounded claims of illegal voting.

He's also waged a battle against the state's lawmakers. Two of them -- House Speaker Nancy Pelosi and House Intelligence Chairman Adam Schiff -- led the push to impeach him.

On his upcoming trip, Trump is expected to visit wealthy enclaves in Los Angeles and the Coachella Valley to collect campaign cash and to discuss water access issues with farmers in the conservative-leaning Central Valley. But otherwise his westerly journey will occur outside the nation's most populous state and its hubs of American entertainment and technology in favor of friendlier territory in states like Arizona and Nevada.

This is a breaking story and will be updated.