Ukraine’s President Volodymyr Zelenskiy on Tuesday dismissed suggestions that his country interfered in the 2016 U.S. presidential election, rubbishing a conspiracy theory promoted by some allies of U.S. President Donald Trump.

Zelenskiy, elected in April, told reporters that Ukraine did not interfere in the elections or the geopolitics of the United States.

Trump has been dogged by allegations that Russia helped him to win the 2016 election. While various investigations have found evidence of Russian meddling, none has linked those actions directly to the U.S. president.

Some in Trump’s inner circle have promoted an alternative theory that — contrary to the findings of U.S. intelligence services — it was Ukraine that interfered in the election to support Trump’s rival, Hillary Clinton.

This theory has been debunked by intelligence officials — the latest being White House adviser Fiona Hill, who said the Ukraine allegations were a “fiction” created by Russia.

“We do not interfere in the elections, in the geopolitics of the United States,” Zelenskiy told journalists in the Estonian capital Tallinn.

A phone call between Zelenskiy and Trump is at the center of attempts to impeach the U.S. leader.

During the conversation, Trump’s opponents say the U.S. leader threatened to withhold military aid until his Ukraine counterpart agreed to investigate an American political rival.

The Democrats pursuing the impeachment inquiry against Trump say the phone call shows he used the office of president to forward his political ambitions.

Zelenskiy sought to play down the importance of the impeachment hearings on his young presidency, telling reporters his country had many problems of its own — a war in the east of the country, separatist-occupied territory and Russia’s annexation of Crimea.

“We have things to do, beyond telephone conversations,” he said.