Similarly, he did not answer whether Trump had expressed concern to Sessions about the attorney general's March decision to recuse himself from the Russian Federation investigation.
Sessions, a senior member of Trump's Cabinet and an adviser to his election team, had a series of tense exchanges with Democrats on the Senate Intelligence Committee during about 2-1/2 hours of high-stakes testimony as they pressed him to recount discussions with the Republican president.
Sessions told Senate panel he did not have a third meeting with Russian ambassador, nor he had any private meetings with any Russian officials at the Mayflower Hotel.
Attorney General Jeff Sessions issued a sweeping denial of any personal involvement in Russian interference in last year's presidential campaign on Tuesday, calling accusations that he even discussed such an effort with officials from that country an "appalling and detestable lie". And asked about Trump's own contention that he fired Comey with the Russian Federation probe in mind, and regardless of any recommendation from anyone else, Sessions said: "I guess I'll just have to let his words speak for themselves".
"Any suggestions I was aware of any collusion or to undermine integrity of the democratic process in an appalling and detestable lie", said Sessions.
Comey's testimony will form a dramatic sequel to Comey's own appearance before the committee last week, and he will have to tackle several open loops that emerged during that appearance, which twisted the knife in an administration that has struggled to extricate itself from the Russian Federation cloud.
He was also "confused" by the "shifting explanations" for his sacking, which came as he led an investigation into any links between the Trump campaign and Moscow.
Following the May meeting in Oslo, North Korea urgently requested another meeting, which took place last week between the USA envoy on North Korea, Joseph Yun, and the North's ambassador at the U.N.in NY.
Later, Comey said he was so uncomfortable that he went to Sessions to "implore" him "to prevent any future direct communication between the President and me". The matter that Comey declined to disclose appears to refer to an ongoing inquiry over whether Sessions failed to disclose a third meeting with the Russian ambassador during a April 16 campaign event for then-presidential candidate Trump.
He also said he recommended FBI Director Comey's firing based on the Deputy Attorney General's report on the situation at the FBI.
Melania Trump, son Barron move into the White House
His daughter and top adviser, Ivanka Trump, is leading events focused on workforce development and college affordability. He had told lawmakers at his January confirmation hearing that he had not met with Russians during the campaign.
"He didn't recall this, but I responded to his comment by agreeing that the Federal Bureau of Investigation and Department of Justice needed to be careful to follow department policy regarding appropriate contacts with the White House", Sessions said.
Lawmakers will also press Sessions about aspects of Comey's testimony last week. "Mr. Comey expressed concern about proper communications protocol with the White House and the president", he said.
Deputy Attorney General Rod Rosenstein says he consults with a career ethics official when questions arise about Attorney General Jeff Sessions' recusal from the Russian Federation investigation. Sources told CNN last week that the attorney general offered to resign after a series of heated exchanges with the President over his decision to recuse himself from the Russian Federation probe.
The hearing will bring contentious questioning for Sessions and likely some uncomfortable moments for the Trump administration. Trump has fired back at Comey, saying he never asked Comey to "pledge allegiance" to him.
USA intelligence agencies concluded in a report released in January that Russian President Vladimir Putin ordered an effort to interfere in the election to help Trump in part by hacking and releasing damaging emails about Democratic candidate Hillary Clinton.
The abrupt dismissal of Comey prompted Trump's critics to charge that the president was trying to interfere with a criminal investigation.
Deputy Attorney General Rod Rosenstein says he will "defend the integrity" of the special counsel's investigation into Russian interference in the USA elections.
Sessions told Trump he was "honored" to be able to serve him. They said they were told their son has been in a coma since his trial - when he was last seen in public - and they had learned of this only one week ago.
When asked if he would do if Trump ordered him to fire Mueller, Rosenstein said, "I am not going to follow any orders unless I believe those are lawful and appropriate orders".