The Trump attorney planned the trip to lobby for an investigation of the former vice president's son, Hunter.
The presidential candidate said it would be "highly unethical" for Trump's personal lawyer to push foreign officials on issues that could benefit the president.
The charges stem from an investigation of former Trump campaign chairman Paul Manafort and his work on behalf of a pro-Russian political party in Ukraine.
The indictments would stem from his lobbying work for Ukraine in 2012.
The strong showing reflects the public longing for a fresh leader who has no links to the corruption-ridden Ukrainian political elite.
Mueller contends that Manafort lied about discussing a Ukraine-related topic with a business associate accused of having ties to Russian intelligence.
Some of the officials reportedly hoped to gauge how they could become influential to the new administration, in order to boost issues favorable to Russia.
Their discussion came one day after Trump canceled a planned meeting, citing the Ukraine-Russia conflict.
The announcement follows President Donald Trump's decision to scrap a meeting with Russian leader Vladimir Putin at the G-20 summit.
The two leaders had planned to meet during the G-20 summit in Argentina this weekend.
Ukraine has voted to impose martial law following the incident, which marks a serious escalation in tensions between the two countries.
The Ukrainian navy said two of its gunboats were struck and Russian crews boarded and seized them and an accompanying tugboat.
There are currently no reports of casualties.
Trump's former campaign chair had a lot of help with his Ukraine lobbying work — and he has agreed to testify anywhere.
Sam Patten, a Paul Manafort associate, pleaded guilty to failing to report his work with a Ukrainian political party to the U.S. government.
Ukrainian intelligence officials staged the reporter's death as part of a special operation to catch the people trying to kill him.
The probe is part of a larger inquiry into Trump's 2016 presidential campaign.
He also said Moscow can "help solve problems" in Ukraine and Syria. 🤔
The clients of the country's only queer-focused shelter are speaking out.
Most Americans were told Donald Trump won the presidential election last year. But his policy toward Russia looks suspiciously