Democrats will block President Donald Trump from giving his State of the Union in the House chamber until the partial government shutdown ends, House Speaker Nancy Pelosi said Wednesday.

In a letter to Trump, Pelosi escalated a standoff over the annual address hours after the president said he would give the speech in the House chamber next week as planned. Earlier this month, Pelosi urged him to reschedule the remarks or deliver them elsewhere during a partial government shutdown.

Pelosi wrote that the Democratic-held House would not pass the resolution needed to approve the joint session of Congress where he would deliver the address. She said lawmakers "will not consider a concurrent resolution authorizing the President's State of the Union address in the House Chamber until government has opened."

"Again, I look forward to welcoming you to the House on a mutually agreeable date for this address when government has been opened," Pelosi wrote. House Minority Leader Kevin McCarthy said he introduced a resolution Wednesday to allow Trump to deliver the address, but it is unlikely to pass without Pelosi's support.

Responding to Pelosi on Wednesday afternoon, Trump told reporters: "I'm not surprised. It's really a shame what's happening with the Democrats. They have become radicalized."

In an earlier letter to Pelosi dated Wednesday, Trump wrote that he will be "honoring your invitation" to speak on Jan. 29. The president said that "it would be so very sad for our Country if the State of the Union were not delivered on time, on schedule and very importantly, on location!"

In a letter to Trump dated Jan. 16, Pelosi requested that the president move the date or location of his address. She cited "security concerns" related to the Secret Service's ability to protect the president during the lapse in funding. The longest shutdown ever is now in its 33rd day.