NORFOLK, Va. (Reuters) - U.S. President Donald Trump declared on Saturday that he has “complete power to pardon,” as his administration confronts ongoing investigations of possible ties between his 2016 campaign and Russia.

U.S. President Donald Trump boards Air Force One for travel to Naval Station Norfolk from Joint Base Andrews, Maryland, U.S. July 22, 2017. REUTERS/Jonathan Ernst

In a series of early morning Twitter messages, Trump aired renewed frustration with his attorney general, the special counsel leading the Russia probe, and Republicans in Congress who are struggling to advance his legislative agenda.

But Trump’s comment about pardons, tucked into an attack on the media, raised the possibility that he was considering his options if the investigations do not turn out the way he hopes.

Trump did not specify who, if anyone, he might consider pardoning. His tweets appeared to be written in response to a report by The Washington Post this week that Trump and his legal team have examined presidential powers to pardon Trump aides, family members and possibly even himself.

Reuters has not confirmed the newspaper accounts.

“While all agree the U.S. President has the complete power to pardon, why think of that when only crime so far is LEAKS against us. FAKE NEWS,” Trump wrote.

The Washington Post, citing current and former U.S. officials, reported on Friday that Russia’s ambassador to the United States was overheard by U.S. spy agencies telling his bosses that he had discussed campaign-related matters with Trump adviser Jeff Sessions last year, when Sessions was a U.S. senator.

Sessions now leads the Justice Department as Trump’s attorney general.

“These illegal leaks...must stop,” Trump tweeted.

At the Senate confirmation hearings for his Cabinet position, Sessions initially failed to disclose his 2016 contacts with Russian Ambassador Sergei Kislyak and later said they were not about the campaign.

In March, Sessions recused himself from the Russia probe. During an interview with The New York Times this week, Trump lashed out at Sessions, saying he would not have chosen him for attorney general had he known Sessions would recuse himself.

Trump, who defeated Democrat Hillary Clinton in last year’s presidential election but continues to use her as a foil, questioned why Sessions and special counsel Robert Mueller were not investigating former FBI Director James Comey or Clinton, for her email practices as secretary of state.

“So many people are asking why isn’t the A.G. or Special Counsel looking at the many Hillary Clinton or Comey crimes. 33,000 emails deleted...,” he tweeted.

PRESIDENTIAL AUTHORITY

Scholars have raised questions about the scope of the president’s legal authority in issuing pardons. If Trump moved to pardon himself sometime in the future, the U.S. Supreme Court might have to decide on the constitutionality, some have speculated.

Trump has not been accused of any wrongdoing by federal investigators who are probing alleged Russian meddling in the 2016 U.S. presidential election.

Mueller is looking into any relationships or contacts between Trump campaign officials and Russians during the election. Congressional committees also are exploring Russia’s influence on the U.S. election.

Trump traveled on Saturday to Norfolk, Virginia, where he spoke at a commissioning ceremony for the aircraft carrier the USS Gerald R. Ford, named for the Republican president who held the White House from 1974-1977.

In his remarks, Trump made no mention of the Russia controversy, focusing his speech on the need for more robust U.S. military spending.

After the trip, Trump retreated to his golf course near Washington and had lunch with his chief of staff, Reince Priebus, policy adviser Stephen Miller and Treasury Secretary Steven Mnuchin and his wife, a White House official said.

Priebus’s presence in the entourage came a day after Trump named a new communications director, Anthony Scaramucci, reportedly over Priebus’s objections.

The weekend trip comes ahead of a busy week of Russia-related activity.

The Senate Judiciary Committee said on Friday that Trump’s eldest son, Donald Trump Jr., and Trump’s former campaign manager Paul Manafort had agreed to negotiate whether to be interviewed by the panel in its Russia investigation.

Trump Jr., Manafort and Jared Kushner, the president’s son-in-law and now one of his senior advisers, all met with Russian lawyer Natalia Veselnitskaya in June 2016. That meeting was held in Trump Tower in New York after the lawyer offered damaging information about Clinton.

The White House is also working on Trump’s campaign promise to U.S. healthcare system.

In his Saturday tweets, Trump had words for Republican senators who have not been able to agree on a way forward to repeal and replace former President Barack Obama’s healthcare law, the Affordable Care Act, which has become known as Obamacare and which Trump promised to do away with as president.

“The Republican Senators must step up to the plate and, after 7 years, vote to Repeal and Replace. Next, Tax Reform and Infrastructure. WIN!” he tweeted.