President Donald Trump may have found himself an unlikely ally in his infrastructure plan: Lloyd Blankfein. The Goldman Sachs  (GS - Get Report) CEO called for the U.S. to up its investments to stay on-par with China in a tweet on Tuesday.

Arrived in China, as always impressed by condition of airport, roads, cell service, etc. US needs to invest in infrastructure to keep up!

— Lloyd Blankfein (@lloydblankfein) June 6, 2017

A person familiar with Blankfein's outlook cautioned against reading too much into the social media post, noting that it emphasizes the need for action without support for any specific plan.

The tweet came a day after the president announced his plan to privatize the nation's air traffic control system as part of a down payment on his infrastructure spending proposal.

The White House has declared this "infrastructure week" in an effort to refocus the conversation on one of the less controversial items on his agenda. Trump is proposing spending $200 billion in federal funding for infrastructure as a catalyst for $800 billion in investments by states, cities and the private sector, amounting to $1 trillion over the course of a decade. 

Compass Point analyst Isaac Boltansky told TheStreet on Monday that the trillion-dollar package is a "pipe dream" at the moment, given the legislative hurdles it would have to pass in Congress and the other items already on the agenda, including healthcare, tax reform and the Russia probe.

Few details on Trump's infrastructure plan have been provided, and no legislation has been drafted.

Blankfein, who supported Hillary Clinton's bid for the presidency, hasn't had a particularly warm relationship with the president, nor has the firm he leads.

While a number of Goldman alumni, including Gary Cohn and Steven Mnuchin, have taken posts in the Trump administration -- fueling speculation that the bank's agenda would benefit -- the company hasn't hesitated to express concern with some of the real estate mogul's Oval Office decisions, Blankfein noted in his annual letter to investors.

Blankfein, who opened a Twitter account in June 2011, said last week in his first-ever post that Trump's decision to leave the Paris climate accord was "a setback for the environment and for the U.S.'s leadership in the world." And in January, when the New York-based bank moved to help employees who might be snared in the president's original attempt at banning travel from some majority-Muslim countries, Blankfein told employees in a voice mail that the move "isn't a policy we support."

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Updated with information on Blankfein, infrastructure plan, Boltansky's comments and person familiar.  James Langford contributed to this story.