UnitedHealth has sought meetings with U.S. President Donald Trump, although it has not secured one yet.

Shares of UnitedHealth fell more than 2% on Tuesday.

The attempts are part of a bolstered lobbying effort in Washington, D.C., by the top U.S. health insurer at a time it faces numerous regulatory challenges, the paper reported.

UnitedHealth has been grappling with high costs and federal investigations, including a criminal one into its Medicare billing practices, which have pushed its share price down around 30% this year. Stephen Hemsley returned to the CEO role in May, after the ouster of Andrew Witty, and promised to regain investor trust.

Hemsley recently met Trump's chief of staff, Susie Wiles, although the criminal investigation was not discussed or brought up by the CEO, a White House official told Reuters.

The WSJ said the meeting covered discussion on the Medicare health insurance program for seniors and the disabled as well as other issues, also citing a White House official.

Hemsley also had dinner with Chris Klomp, the official overseeing Medicare in the summer, and discussed Medicare-plan billing policies and supplemental benefits offered under private Medicare plans, the newspaper said.

In response to Reuters' request for comment, UnitedHealth said "public policy shapes healthcare across America, and it's our responsibility to engage with the administration and Congress at all levels to improve patient access and affordability," adding that it is especially true now "as critical decisions are being made."

Kush Desai, a White House spokesperson, told the WSJ the Trump administration "routinely meets with insurers to deliver on the President's mandate of improving healthcare and lowering costs for everyday Americans."