The US accused ZTE of misleading American regulators after it settled charges of violating sanctions against North Korea and Iran.
The US Department of Commerce issued the trade ban following its determination of a violation of terms ZTE had agreed to after it was found selling embargoed technology to Iran in 2012.
Trump's reversal will likely have a significant impact on ZTE's USA suppliers such as Qualcomm and Intel.
Trump's offer for aid comes at a moment of sky-high trade tensions between the United States and China.
Given ZTE's operations are now mostly suspended and not bringing in revenue for the company, whatever negotiations take place in the next two weeks are of vital importance in determining the company's future.
Man City record will be tough to break-Guardiola
Salah, who was named EPL Player of the Season earlier on Sunday, netted the goal 26 minutes into the match, and Dejan Lovren added a second goal 14 minutes later.
"Too many jobs in China lost", Trump wrote.
The ban is the result of ZTE's failure to comply with that agreement, the Commerce Department said.
The White House did not immediately respond to a request for comment.
Trump has repeatedly blasted China for what he calls unfair trade practices. There's clearly a gap of thinking between the President and the rest of government. If Trump was announcing a huge concession with his tweet, it was without any indication of what he might have gotten in return.
The widening trade dispute between the world's two biggest economies has taken a toll on both sides.
But the company's run into problems in the U.S in recent years.
She Was Forced to Marry. He Raped Her, So She Killed Him
Sudan is ranked as one of the worst countries in the world for gender inequality with violence against women and girls rampant. Because Noura was a victim of rape, many are calling for her release, and for her not to be punished at all.
The US government launched an investigation into ZTE after Reuters reported in 2012 the company had signed contracts to ship millions of dollars' worth of hardware and software from some of the best known US technology companies to Iran.
The US's only major telecom equipment maker, Lucent Technologies, was acquired by France's Alcatel SA in 2006, with the combined company later absorbed into Finland's Nokia Oyj.
ZTE was also handed a seven-year suspended denial of export privileges, which the commerce department made a decision to activate last month after determining the company had lied about its handling of the matter.
But ZTE still relies on USA companies to supply it with components for its networking gear.
Prior to announcing his run for president, meanwhile, Trump frequently tweeted about China stealing U.S. jobs. Both sides had been expected to dig in for a fight over their trade imbalance at this week's talks. "But be cool, it will all work out!" That cut off access to the U.S. technology it needs to build most of its products, from Qualcomm Inc.'s semiconductors to optical chips from Lumentum Holdings Inc.
The U.S. imposed the penalty on Shenzhen-based ZTE after discovering that the company, which had paid a $1.2 billion fine in the case, had failed to discipline employees involved and paid them bonuses instead. "This egregious behavior can not be ignored".
Pyongyang: Nuclear test site will be dismantled between May 23-25
Pyongyang has scheduled the dismantlement of its nuclear test site for sometime between May 23 and 25 depending on the weather. Kim revealed plans to shut down the nuclear test site during his summit with South Korean President Moon Jae-in last month.
Even with Trump's unexpected backing, ZTE is up against it to roll back the sanctions.