President Trump has spoken privately with Russia’s Vladimir Putin at least 16 times since he entered office in 2017. These conversations have long been the subject of scrutiny and speculation, given the Kremlin’s interference in the election that brought Trump to power.

Now, with Trump’s private interactions the subject of a broader scandal after the release of a partial rough transcript of his July 25 conversation with Ukraine’s president, Trump’s conversations with Putin are being viewed with renewed interest.

House Intelligence Committee Chairman Adam B. Schiff (D-Calif.) has said that Congress is particularly interested in finding the records of Trump’s calls with Putin, especially if they had been stored in an unorthodox way. The Kremlin initially said it did not want the conversations made public, though Putin said Wednesday that he would not be against it.

Accounts of Trump’s private conversations with other senior Russian officials have already drawn criticism, including one in the Oval Office in 2017 in which Trump said he was unconcerned about Kremlin election interference. The remarks prompted the White House to limit access to the remarks, former officials told The Washington Post.

Below is a timeline of what is publicly known about Trump and Putin’s conversations through phone calls and in person.

Jan. 28, 2017

Trump and Putin shared a congratulatory call after Trump’s inauguration. A White House readout of the call said that it lasted about an hour and included discussions about Syria and the threat posed by the Islamic State and that the “positive call was a significant start to improving the relationship between the United States and Russia that is in need of repair.”

According to subsequent reporting from Reuters, Putin raised the possibility of extending a 2010 treaty that caps U.S. and Russian deployment of nuclear warheads. Trump asked aides what the treaty, known as New START, was before denouncing it, Reuters reported.

April 3, 2017

Trump called Putin after a terrorist attack on the St. Petersburg subway. According to the White House readout, Trump “expressed his deepest condolences to the victims and their loved ones, and to the Russian people.”

May 2, 2017

Trump and Putin spoke by phone about Syria and North Korea, according to the White House.

July 7, 2017

The two leaders meet for the first time in person on the sidelines of the Group of 20 summit in Hamburg. The meeting was also attended by then-Secretary of State Rex Tillerson and interpreters, who later told reporters that the meeting had lasted two hours and covered the war in Syria.

The Post later reported that Trump had taken the unusual step of taking notes from his own interpreter after the meeting and instructing the employee not to discuss the details of the meeting, effectively limiting the amount of information other officials could learn about the meeting.

Trump also informally spoke with Putin at a dinner for the G-20 leaders later in the day. The U.S. president approached his Russian counterpart, and the only other party to the conversation was Putin’s interpreter, according to officials present.

Nov. 11, 2017

Though the White House said there would be no formal meeting between Trump and Putin at the Asia-Pacific Economic Cooperation meeting in Danang, Vietnam, the U.S. president later said he had spoken to the Russian leader informally at the event.

Trump said he had “two or three” brief conversations with Putin that mostly centered on the war in Syria and Russian election interference. “He said he didn’t meddle,” Trump told reporters on Air Force One.

Nov. 21, 2017

Trump and Putin spoke for an hour on the phone about the U.S.-Russia relationship and the conflict in Syria, according to the White House.

Dec. 14, 2017

Trump spoke with Putin on the phone to thank him for “acknowledging America’s strong economic performance in his annual press conference,” according to the White House, which said the pair also talked about North Korea.

Dec. 17, 2017

Putin called Trump to thank him for the warning that U.S. intelligence agencies gave Russia about a terrorist plot in St. Petersburg, according to the White House.

“President Putin extended his thanks and congratulations to Central Intelligence Agency (CIA) Director Mike Pompeo and the CIA,” the readout said. “President Trump then called Director Pompeo to congratulate him, his very talented people, and the entire intelligence community on a job well done!”

Feb. 12, 2018

Trump called Putin to offer his condolences after a plane crash in Russia killed 71 people, according to the White House, which also said that the two leaders discussed the Israel-Palestinian peace process and North Korea.

March 20, 2018

Trump called Putin after his reelection to the Russian presidency to congratulate him, according to the White House. The Post later reported that Trump had been given briefing notes that warned him “DO NOT CONGRATULATE” before the call.

A week later, the Kremlin said that Trump had proposed meeting Putin at the White House for the Russian leader’s first visit since 2005.

July 16, 2018

Trump and Putin met face-to-face again for a bilateral summit in Helsinki. The two leaders spoke for two hours, joined only by their interpreters, before holding a 46-minute news conference in which Trump said that Putin had made an “extremely strong and powerful” denial that Russia interfered with the U.S. election.

A full account of what was discussed in the private meeting has never been offered, despite lawmakers’ attempts to get interpreters’ notes from the discussion.

Limited and sometimes contradictory accounts of the talks have leaked out. According to The Post, John Bolton, national security adviser at the time, told senior officials that Trump had told Putin that U.S. troops would stay in Syria until Iranians left. Kremlin officials have spoken of “agreements” reached during the meeting, without going into specifics.

Nov. 30, 2018

Trump and Putin were both at the G-20 summit in Buenos Aires, but the U.S. president canceled a planned meeting just hours after the Kremlin had announced it, blaming the decision on Russia’s seizure of Ukrainian naval ships and sailors in the Black Sea.

However, the Financial Times later reported that the two world leaders and their wives had talked for 15 minutes at an event at the Buenos Aires opera house. An unnamed Russian official told the newspaper that the discussion had been about whether they could meet formally, as well as the situations in Ukraine and Syria, and that only a Russian interpreter was present.

May 3, 2019

Trump told reporters that he and Putin discussed the end of special counsel Robert S. Mueller III’s investigation into Russian interference in the 2016 election during a phone call but that he didn’t tell Putin not to interfere in the next election.

Then-White House press secretary Sarah Sanders had told reporters earlier in the day that the call lasted slightly more than an hour and also included discussion of nuclear agreements, North Korea, Venezuela and trade.

June 28, 2019

Trump met with Putin one the sidelines of the G-20 summit in Osaka, Japan. The two leaders met for 90 minutes, mostly without journalists present. Russian state media reported that Putin invited Trump to Moscow to celebrate the 75th anniversary of the end of World War II in 2020.

Before the private meeting, Trump was asked by journalists whether he would warn Putin not to interfere in future U.S. elections, prompting the U.S. president to jokingly reprimand the Kremlin leader. “Don’t meddle in the election,” Trump said while wagging a finger.

July 31, 2019

Trump and Putin spoke by phone to discuss wildfires in Siberia and trade between the two nations, according to the White House. The call was first announced by the Russians, and the U.S. statement came hours after the Kremlin released its own account of the call.