President Trump on Thursday blasted FBI agent Peter Strzok for refusing to answer “many questions” in his closed-door grilling on Capitol Hill this week -- and took a shot at Special Counsel Robert Mueller over alleged "Conflicts of Interest."

“Lover FBI Agent Peter Strzok was given poor marks on yesterday’s closed door testimony and, according to most reports, refused to answer many questions. There was no Collusion and the Witch Hunt, headed by 13 Angry Democrats and others who are totally conflicted, is Rigged!” Trump tweeted early Thursday.

The president’s tweet comes after Strzok’s hours-long closed-door testimony before the House Judiciary Committee on Wednesday. It was his first congressional appearance following revelations of numerous anti-Trump messages he exchanged with bureau colleague Lisa Page during the 2016 presidential campaign. Strzok and Page were romantically involved.

Trump’s mention of the “13 Angry Democrats” is in reference to attorneys and investigators on Mueller’s team. Thirteen of 17 investigators have registered as Democrats. Mueller, though, is said to be a lifelong Republican and served as FBI director under former Republican President George W. Bush.

Trump went on to blast Mueller on Thursday, pressing him to "list his Conflicts of Interest."

"When is Bob Mueller going to list his Conflicts of Interest? Why has it taken so long? Will they be listed at the top of his $22,000,000 Report..." Trump tweeted. "And what about the 13 Angry Democrats, will they list their conflicts with Crooked H?"

He continued: "How many people will be sent to jail and..........persecuted on old and/or totally unrelated charges (there was no collusion and there was no obstruction of the no collusion)...And what is going on in the FBI & DOJ with Crooked Hillary, the DNC and all of the lies? A disgraceful situation!"

While Trump did not specify what "conflicts" he was referring to, past reports have raised questions about Mueller's ties to fired FBI boss James Comey and his ties to a uranium deal case. Mueller supervised a bribery probe involving a subsidiary of Russia’s Rosatom, which eventually got approval from the U.S. to buy a Canadian mining company that controlled a swath of American uranium reserves.

Republicans want to know how that deal was approved despite the evidence gathered in the bribery probe.

As for Strzok, the DOJ inspector general report revealed the hundreds of messages between Strzok and Page included one in which Strzok vowed to “stop” Trump from becoming president.

But a spokeswoman for House Judiciary Committee Chairman Bob Goodlatte, R-Va., said Strzok did not answer many questions he was asked Wednesday.

“Today Peter Strzok appeared before our Committees to answer questions regarding his actions while leading the FBI investigation into Hillary Clinton’s use of a private email server. Unfortunately, FBI counsel ordered Mr. Strzok not to answer many of the legitimate questions he was asked,” Kathryn Rexrode said in a statement to Fox News Wednesday. “We intend to hold a public hearing soon. I hope he will be more forthcoming at that time.”

“There are still a lot of unanswered questions on who knew what when,” House Freedom Caucus Chairman Mark Meadows, R-N.C., told reporters on the Hill during a break from the hearing Wednesday. “And as it related to this particular investigation, what was the genesis of the Russia collusion investigation?”

Meadows said that “new information has come out,” but did not share specifics. While it is unclear what specifically was learned in the confidential hearing, a GOP source told Fox News that most GOP members have focused on the Russia investigation and how Strzok relates to the beginning of that probe.

DOJ Inspector General Michael Horowitz confirmed last week that he is investigating whether Strzok’s anti-Trump bias factored into the launch of the FBI’s Russia investigation.

Strzok, 48, appeared before the committee voluntarily, despite being issued a subpoena over the weekend.

Strzok, who was escorted from his FBI office last week in what bureau veterans have described as an “extraordinary” step, has been under scrutiny for months over the series of politically charged text messages exchanged with Page, who left the bureau in May.

Both were assigned to Mueller’s investigation into Russian meddling and potential collusion with Trump campaign associates in the 2016 presidential election. Page’s assignment ended in July 2017. Strzok was removed from the team later in 2017 following revelations of his anti-Trump text messages.

Trump also said Thursday that Strzok took "orders" from Comey and former FBI Deputy Director Andrew McCabe, further suggesting that Comey and Mueller are "best friends."

"Peter Strzok worked as the leader of the Rigged Witch Hunt for a long period of time -- he got it started and was only fired because the gig was up. But remember, he took his orders from Comey and McCabe and they took their orders from you know who. Mueller/Comey best friends!" Trump tweeted.

The inspector general’s report, released earlier this month, noted that it was specifically concerned about text messages exchanged between FBI officials Strzok and Page that “potentially indicated or created the appearance that investigative decisions were impacted by bias or improper considerations.”

“I don’t know how any reasonable person reads the texts and would suggest there was no bias,” Meadows told reporters. “None of my concerns about political bias have been alleviated based on what I’ve heard so far.”

But the inspector general ultimately found no evidence that the anti-Trump bias among several FBI agents impacted prosecutorial decisions in the Clinton email probe.

Trump also tweeted Thursday morning questioning why former FBI Director James Comey and other “disgraced” bureau officials did not “closely examine” Russian meddling during the election — further questioning why Hillary Clinton’s Russia ties are not investigated.

“Russia continues to say they had nothing to do with Meddling in our Election! Where is the DNC Server, and why didn’t Shady James Comey and the now disgraced FBI agents take and closely examine it? Why isn’t Hillary/Russia being looked at? So many questions, so much corruption!” Trump tweeted.

The president's tweet comes amid planning for a summit with Russian President Vladimir Putin.

Fox News' John Roberts and Chad Pergram contributed to this report.