The secretary of state is preparing an argument that the U.S. remains a participant in the Obama-era nuclear deal, with the goal of extending an arms embargo or destroying the accord.

As accusations swirled Sunday about Russia’s efforts to interfere with the 2020 election, President Trump’s national security adviser and former Vice President Joseph R. Biden Jr. could not agree on what Moscow is, or is not, doing.

Their disagreement came as intelligence officials disputed reports that emerged last week about a briefing of the House Intelligence Committee. The officials now maintain that the House members either misheard or misinterpreted a key part of the briefing, and that the Office of the Director of National Intelligence did not mean to say that it believes the Russians are currently intervening in the election explicitly to help President Trump.