(CNN) President Donald Trump reiterated his threat Monday to shut down the government if Congress fails to pass new border security and immigration measures, but he declined to draw a line in the sand.

Trump stuck to broad strokes as he warned he is willing to shut down the government if Congress does not take action, saying he would "always leave room for negotiation" and offering no specific funding threshold or legislative marker.

"If we don't get border security after many, many years of talk within the United States, I would have no problem doing a shutdown," Trump said during a joint news conference at the White House alongside Italian Prime Minister Giuseppe Conte. "It's time we have proper border security. We're the laughingstock of the world. We have the worst immigration laws anywhere in the world."

Trump's comments came after he threatened on Twitter over the weekend to shut down the government if he does not receive funding for his campaign-promised border wall from Congress.

While he spoke specifically about border wall funding on Twitter, Trump on Monday did not take a firm stance on his must-fund priorities. Instead, he simply ticked down a list of border security funding priorities and immigration reforms that he would like to see.

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