Poroshenko -- who is viewed as an enemy to Russian leaders in Moscow -- was scheduled to "drop by" a meeting with President Donald Trump and national security adviser H.R. McMaster during his previously scheduled visit with Vice President Mike Pence, according to the White House schedule.
Trump told reporters, briefly allowed into the room, that "a lot of progress has been made" in relations between the United States and Ukraine. The White House also put out a short, direct official read out of the meeting, noting that the two spoke about a "peaceful resolution to the conflict in eastern Ukraine and President Poroshenko's reform agenda and anti-corruption efforts."
Arriving at the West Wing on Tuesday morning, Poroshenko wasn't greeted by Trump -- as the President has been known to do with other leaders -- and walked into the West Wing quietly and without fanfare. Poroshenko will primarily meet with Pence, who advisers say has a close relationship with the Ukrainian leader.
In a nod to Poroshenko, the Trump administration announced more sanctions against separatists, including some Russians, involved in the conflict in Ukraine as the president arrived at the White House.
Treasury Secretary Steven Mnuchin said the sanctions against 38 individuals
are designed to "maintain pressure on Russia to work toward a diplomatic solution."
Poroshenko's treatment is noteworthy given Trump's tendency to roll out the red carpet for almost all foreign leaders who visit the White House -- even those from small countries with few pressing issues in the United States.
Romanian President Klaus Iohannis stood next to Trump for a bilateral press conference
earlier this month. And Monday, Panamanian President Juan Carlos Varela was greeted by Trump and first lady Melania Trump on the South Portico of the White House, enjoyed a long walk along the colonnade and a one-on-one bilateral meeting with the President in the Oval Office.
Other foreign leaders have been given muted welcomes when meeting with Pence, not Trump. King Abdullah II of Jordan met with Pence at his residence earlier this year and did not officially meet with Trump, while Honduran President Juan Orlando Hernández met with the vice president in March without much fanfare.
But the subdued meetings are more rare.
Despite the less-than-warm welcome, Trump and Poroshenko -- on paper -- would seem to have a lot in common. The duo are both new to politics and built sizable empires in business. Poroshenko, a billionaire, owns Roshen, a large candy company, and 5 kanal, a Ukrainian broadcast company and Trump regularly touts his business acumen, his wealth and the fact he is new to politics.
Multiple senior Trump administration officials pushed back against the idea that Poroshenko was snubbed by the White House, saying he got more face-time with top Trump officials than other world leaders.
"Not all visits are the same," the official said, arguing that Poroshenko saw "all the senior most people in the building," including one-on-one time with Trump, Pence and McMaster.
The official said visits are "different every time" and this sort of visit is not a "uniquely Trump thing."
Critic of Putin
Most notably, the muted welcome is striking given the Ukrainian leader's reputation a vocal critic of Russian President Vladimir Putin, whose meddling in the 2016 election and subsequent investigations into the Trump campaign's ties to Russia have largely overshadowed the first few months of the Trump presidency.
Close ties between Trump and a Ukrainian leader like Poroshenko would likely anger leaders in Russia, who have blamed the United States for conflict in Eastern Ukraine, where fighting between Ukrainian forces and Russian backed groups continues.
Poroshenko, who was elected in 2014, told CNN in 2016
that Putin wants "the whole Ukraine" to be part of the "Russian Empire."
Trump also has personal ties to anti-Poroshenko Ukrainians. Paul Manafort, the former head of Trump's campaign, did lobbying work
with President Viktor Yanukovych, the former president of Ukraine who has been critical of Poroshenko's handling of Russia's efforts to annex Ukrainian territory.
The pseudo-snub is a dramatic break from the Obama administration, too. Former President Barack Obama and Vice President Joe Biden were close with Poroshenko
during their two overlapping years, as Russia's actions in the area drew strong condemnations from Obama.
Biden even made Poroshenko part of his swansong foreign trip, visiting Ukraine days before Trump was inaugurated.
In addition to meeting with Trump, Poroshenko will meet with Secretary of State Rex Tillerson and Secretary of Defense James Mattis on Tuesday.