National security adviser H.R. McMaster said Thursday that Trump will meet with Putin along the sidelines of the annual Group of 20 meeting in Hamburg, Germany, part of an itinerary that will include meetings with several world leaders.

Trump will face the challenge of working with Russia toward common goals in Syria and Ukraine, while also potentially broaching allegations about Moscow’s interferences in the U.S. elections and accusations that some of his associates may have had contact with Russian officials during the 2016 campaign and the transition.

All 17 U.S. intelligence agencies have agreed that Russia was behind last year’s hack of the Democratic Party’s email systems and tried to influence the 2016 election to benefit Trump.

Trump will be under pressure to side with the U.S. intelligence agencies and press Putin on the issue of election meddling, something he has thus far been reluctant to do. Trump’s promise of closer cooperation with Russia has prompted concerns that the U.S. will have diminished leverage over global issues and he could be more sympathetic to Russia.

Trump has staunchly denied that he had any contacts with Russia during his campaign. Russian officials have denied any meddling in the 2016 election.

“Putin is all about optics and symbolism,” said Julianne Smith, a National Security Council and Defense Department official under President Barack Obama. “He wants the meeting and the photo more than the discussion.”

Putin’s spokesman Dmitry Peskov told Russian news agencies after the White House’s announcement that Putin is expecting to meet with Trump in Hamburg. They “will meet at the summit in one way or another. We have said it before,” he told state-owned RIA Novosti news agency.

McMaster and White House economic adviser Gary Cohn would not say whether the president intends to address accusations that Russia interfered in the 2016 presidential election, saying the agenda is “not finalized” for this or any other meeting.

“Our relationship with Russia is not different from that with any other country in terms of us communicating to them really what our concerns are, where we see problems with the relationship but also opportunities,” McMaster said.

Many administration officials believe the U.S. needs to maintain its distance from Russia at such a sensitive time—and interact only with great caution.

Some advisers have recommended that the president instead do either a quick, informal “pull-aside” on the sidelines of the summit, or that the U.S. and Russian delegations hold “strategic stability talks,” which typically don’t involve the presidents, according to current and former administration officials.

The officials spoke on condition of anonymity because they weren’t authorized to discuss private policy matters by name.

The U.S.-Russian relationship deteriorated during Obama’s eight years in office when the Obama administration slapped sanctions on Moscow over its annexation of Crimea from Ukraine. Trump frequently said that he was hopeful of improving American ties with Russia.

But major disagreements remain over Ukraine and Syria, and Trump said in April that U.S-Russian relations “may be at an all-time low.”

Russia has sought to put itself on an equal footing with the U.S. since the collapse of the Soviet Union, extending its territory where it can, countering U.S. military action and positioning itself as a rival to the world’s biggest economy.

McMaster said Secretary of State Rex Tillerson is taking the lead on the discussions and “has been engaged in a broad, wide-range discussion about irritants, problems in the relationship but also to explore opportunities, where we can work together, areas of common interest. So it won’t be different from our discussions with any other country.”

Trump will kick off his second foreign trip in Warsaw, Poland, where he plans to deliver a major speech at Krasinski Square, the site of the memorial to the 1944 Warsaw Uprising against the Germans during World War II.

In Warsaw, Trump will meet with Polish President Andrzej Duda and attend a summit with a dozen European and Baltic leaders devoted to the Three Seas Initiative. The initiative is an effort to expand and modernize energy and infrastructure links in a region of Central Europe from the Baltic Sea in the north to the Adriatic and Black seas in the south.

In addition to Putin, Trump planned to meet with the leaders of several other countries during the G20, including the United Kingdom, Germany, China, South Korea, Mexico, Indonesia and Singapore, White House officials said.