WASHINGTON — The U.S. is prepared to quickly lift sanctions on North Korea and promise its leader, Kim Jong Un, that it would not seek to oust him from power, senior officials said Sunday, sketching out the terms of a possible deal if Kim agrees to give up his nuclear weapons.

“We will have to provide security assurances” to Kim as part of a nuclear deal, Secretary of State Mike Pompeo said on “Fox News Sunday.” “Our hope is that Kim wants a strategic change, and President Trump is prepared to help.”

U.S. officials emphasized that they are not close to finalizing an agreement with Kim, a month before he and President Donald Trump are scheduled to meet at an unprecedented summit in Singapore. They also stressed that Kim will have to agree to sweeping concessions up front, unlike in previous nuclear deals with Pyongyang that were phased in and ultimately fell apart.

“We’re prepared to open trade and investment as soon as we can,” John Bolton, Trump’s national security adviser, said on ABC’s “This Week.” Before that can occur, he added, “We want to see the denuclearization process so completely under way that it’s irreversible.”

Separately Sunday, Trump vowed to help smart phone and telecom equipment maker ZTE, only weeks after the U.S. banned American companies from selling parts to the Chinese company for seven years.

The Commerce Department found ZTE had failed to abide by an agreement reached after it was found to have illegally shipped goods to Iran. The president’s surprise move was seen as a concession to China, whose cooperation will be critical to the success of the North Korea talks.

Trump said in a tweet that he and China’s president, Xi Jinping, “are working together to give massive Chinese phone company, ZTE, a way to get back into business, fast. Too many jobs in China lost. Commerce Department has been instructed to get it done!”

It remains unclear whether Trump’s advisers have reached agreement among themselves about their negotiating goals and how far they are prepared to push North Korea.

Bolton appeared to widen the scope of U.S. demands, insisting that the U.S. also wanted to put elimination of North Korea’s chemical and biological weapons and other issues on the table.

“I think we need to look at their chemical and biological weapons programs,” and the return of South Korean and Japanese citizens abducted by the North, Bolton said.

Pyongyang has long sought assurances the U.S. would not invade the North and is believed to have pursued nuclear weapons in an attempt to ensure the survival of the regime by raising the threat that any U.S. move to oust Kim could escalate into nuclear war.