President Donald Trump will meet privately with his Russian counterpart, Vladimir Putin, on the sidelines of next week’s G20 summit — and he has asked aides to identify bargaining chips he can trade away during the discussion.

The president has asked national security council staff to come up with a list of “deliverables” to offer in his conversations with Putin, reported The Guardian.

Two former officials who are familiar with the preparations told the newspaper that Trump may offer to return two diplomatic compounds in the U.S. vacated by the Russians on orders of the Obama administration in response to the Kremlin’s election interference.

It’s not clear what Putin might be asked in return, the sources said.

Former President Barack Obama ordered Russian officials to leave the compounds in Maryland and New York, which he said were used for intelligence-related purposes, and expelled 35 Russian officials he described as intel operatives.

The Trump administration considered handing back the compound early last month if Russia would permit the construction of a new U.S. consulate in St. Petersburg, but that agreement was scrapped a few days later after Secretary of State Rex Tillerson met with Russian foreign minister Sergey Lavrov.

Officials with the National Security Council and State Department strongly object to offering one-sided concession aimed at improving the tone of U.S.-Russia relations, The Guardian reported.

“They have been asked for deliverables, but there is resistance to offering anything up without anything back in return,” one former official told the newspaper.

Administration officials also are uneasy with Trump’s insistence on meeting personally with Putin at the G20 summit in Germany, although national security adviser H.R. McMaster confirmed the two leaders would meet on the sidelines in Hamburg.

Trump and his campaign associates are under investigation by Congress and the Justice Department for possible ties to Russia before the election, as well as possible efforts afterward to conceal those ties.

The president has made efforts since his election to lift sanctions imposed on Russia for interfering in Ukraine, and Congress is considering legislation to lock those sanctions in place by law.

The measure passed 98-2 in the Senate, but the bill has stalled in the House over technicalities as the White House reportedly seeks to water down its penalties.