WASHINGTON — US President Donald Trump said Wednesday he intends to deliver his State of the Union speech to a joint session of Congress next week, dismissing House Speaker Nancy Pelosi's argument that adequate security can't be provided during the partial government shutdown.

"I will be honoring your invitation," he told her in a letter, referring to her pro forma invitation weeks ago before she pulled away from the welcome mat.

Pelosi asked Trump last week to postpone the speech or deliver it in writing. But Trump said in his letter: "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!" Trump's letter is the latest move in a game of brinkmanship between the president and Pelosi as they remain locked in an increasingly personal standoff over Trump's demand for border wall money that has forced a partial government shutdown, now in its second month.

In asking him last week to make other plans, Pelosi stopped short of denying him the forum. Now the White House, in essence, is calling her bluff. Even so, White House officials have been working on a backup plan to have him give the speech somewhere else if Democrats don't let him do it in the traditional forum, the House chamber, on Tuesday.

Trump aide Kellyanne Conway said it would be "remarkably petty" for the speaker to deny Trump the location.

Each side has been accusing the other of pettiness since Pelosi raised doubts about the speech and Trump followed up by revoking her use of a military aircraft, thereby canceling a congressional delegation visit to Afghanistan.

The president cannot speak in front of a joint session of Congress without both chambers' explicit permission. A resolution needs to be approved by both chambers specifying the date and time for receiving an address from the president.

The Republican leader in the House, Kevin McCarthy, said the address should be "in the House chamber as we have always done. This is not the time to play politics." But Democratic Rep. Hakeem Jeffries of New York said: "Unless the government is reopened, it's highly unlikely the State of the Union is going to take place on the floor of the United States House of Representatives." Trump said the Homeland Security Department and the Secret Service assured him there would be "absolutely no problem regarding security" for the State of the Union and "they have since confirmed this publicly." Officials have been considering potential alternative venues for the Jan. 29 speech, including a rally-style event, an Oval Office address— as Pelosi previously suggested — a speech in the Senate chamber, and even a visit to the Mexican border. Multiple versions of the speech are being drafted to suit the final venue.

The Constitution states only that the president "shall from time to time give to the Congress Information of the State of the Union," meaning the president can speak anywhere he chooses or give his update in writing.

But a joint address in the House chamber, in front of lawmakers from both parties, the Supreme Court justices and invited guests, provides the kind of grand backdrop that is hard to mimic and that this president, especially, enjoys.

Still, North Carolina's House speaker, Tim Moore, has invited Trump to deliver the speech in the North Carolina House chamber. Michigan House Speaker Lee Chatfield has offered his state capitol. Trump spoke with both of them this week, according to Moore's office and a tweet from Chatfield.

Pelosi in her letter last week questioned whether the Secret Service and Homeland Security could provide adequate security for the speech to Congress given that they are operating without money.

In their standoff, Trump has accused Pelosi of behaving "irrationally," while Pelosi has refused to negotiate with Trump on money for his proposed border wall until he agrees to reopen the government.

Associated Press writers Kevin Freking, Andrew Taylor, Catherine Lucey and Jonathan Lemire contributed to this report.

AP