The battle over US President Donald Trump’s border wall – one of his most important campaign promises – has continued into the new year, with both sides of the political aisle digging in.

At stake is funding for the federal government, which has been partially shut down due to an impasse regarding funds for the wall. The president has said he will refuse to sign legislation to finance government without at least $5.6 billion earmarked for a physical border barrier.

The Democratic congressional leadership, now with a majority in the House of Representatives, has said that it will provide no funding for a wall, and that a vote on opening the government should be separate from the contentious issue.

Following a meeting with the president on Friday, Democratic Senate Minority Leader Chuck Schumer said Trump expressed a willingness to keep government agencies shuttered for “months or even years.”

That sentiment was supported by Senate Republican Richard Shelby, chairman of the Senate Appropriations Committee, who said that the partial shutdown may go on for “months and months.”

Both sides appear to see standing firm as a smart political decision. Democrats have cited recent polls that show that a majority of Americans are opposed not just to Trump’s current strategy of holding up funding for the government, but are also not sold on the need for an uninterrupted physical wall across the southern border.

The Trump administration, meanwhile, is keen on keeping support among the president’s core political base, which is broadly in favor of not backing down. Additionally, according to one recent poll which showed a lack of majority support for the wall itself, a slim majority of respondents – 51% – felt that the Democrats should give Trump some wall funding as a compromise.

Democratic House Speaker Nancy Pelosi has said she would not support any funding that would go toward a physical wall, joking, however, that she would consider giving $1.