U.S. President Donald Trump takes a question during a press conference in the Rose Garden of the White House following a meeting with Congressional leaders on the government shutdown, Jan. 4, 2019 in Washington, D.C., the United States. (AFP Photo)

WASHINGTON, Jan. 4 (Xinhua) -- U.S. President Donald Trump said Friday that he's prepared for a partial government shutdown to last for months or years, after his meeting with Congressional leaders yielded no deal on funding for a U.S.-Mexico border wall.

Speaking to reporters from the White House Rose Garden, Trump said he wouldn't reopen the government until a dispute between the White House and Democrats over border security is resolved.

"We won't be opening until it's solved. We think this is a much bigger problem," the president said, adding it is a problem of national security.

About a quarter of the federal government shut down last month due to an impasse between the White House and the Congress over whether to provide billions of U.S. dollars for the construction of a border wall, a signature campaign promise Trump made during his presidential campaign.

Trump and his conservative allies have insisted that the wall is essential to addressing illegal immigration and drug trafficking, while Democrats have slapped the proposal as an "inefficient, unnecessary and costly" solution to strengthening border security.

The president dug in on his proposal on Friday, saying, "We have to get a structure built," while attempting to strike a positive tone about his meeting with Democratic leaders at the White House, the second time in three days.

He described the meeting as productive and said both sides are "on the same path in terms of wanting the government open," adding that a working group led by Vice President Mike Pence will work through the weekend on ending the standoff.

Democrats were less upbeat. Newly-elected House Speaker Nancy Pelosi said the meeting, which last nearly two hours Friday noon, was "lengthy and sometimes contentious," though admitting progress has been made.

Senate Minority Leader Chuck Schumer told reporters after the meeting with Republicans that "a bunch of issues" were discussed but "it's very hard to see how progress will be made unless they open up the government."

The partial shutdown was on its 14th day on Friday as some 800,000 federal workers were left furloughed or working without pay.

House Democrats passed a spending package Thursday night, including a stopgap bill to keep the Homeland Security Department funded at the current level until Feb. 8, and measures to fund the eight other cabinet departments affected by the shutdown through Sept. 30, the end of the fiscal year.

However, those measures are unlikely to clear the Republican-held Senate or be signed by Trump as they do not provide money for the proposed border wall.