The meeting, expected in the next week, reflects concern in the Republican hierarchy that he could attract enough conservative voters to deprive the party of its longed-for victory in next year's presidential election. Jim Nicholson, the chairman, will make a personal apppeal to Mr Buchanan.
The prospect of a defection has appalled Republican stalwarts since the first murmurs of Mr Buchanan's restlessness were heard early this summer. They took on a sudden urgency this week with reports from the most reliable of sources, Mr Buchanan's sister, Bay - a television presenter and his unofficial "agent" - that he was "seriously considering" joining the Reform Party with a view to becoming its presidential candidate. "I think it is an incredible opportunity," said Ms Buchanan. "And there is a big cry across the country for a third party candidate."
She has been in negotiations on her brother's behalf with leaders of the Reform Party since before its convention in July. There, effective control of the party passed from the party's billionaire founder, Ross Perot, to a group associated with the independent libertarian, Jesse Ventura, who was elected Governor of Minnesota last year.
The transfer of control opened the way for someone other than Mr Perot to be nominated as the party's presidential candidate, and one of the names mentioned was that of Mr Buchanan. At that stage, Mr Buchanan was cautious, stating that his preference was to remain with the Republican Party. But he also warned that if he moved, it would be because he felt that the party had "left" him, rather than because he was leaving the party. Mr Buchanan, an accomplished campaigner, public speaker and television talk show participant, represents the Christian conservative, protectionist wing of the party and has made no secret of his view that George W Bush is moving the party to the political centre for the sake of electoral advantage.
With the party hierarchy united around Mr Bush as the party's most plausible candidate for the White House, Mr Buchanan has little hope of effecting an upset in the primaries and so has little to lose from bolting.
But if Mr Buchanan could benefit from joining the Reform Party, the Republican Party stands to lose a great deal. Mr Buchanan has a loyal conservative following of his own that could well choose to defect with him rather than stay in a Republican Party gathered around Mr Bush. He could also tap into a growing constituency of Republican voters that resents the huge fund-raising lead built up by Mr Bush - he has now raised close to $50m (pounds 33m), a record for any candidate at this stage - and the way party officials are presenting his nomination, if not his election, as inevitable.
There remain questions about how easily the traditionalist Mr Buchanan would fit into the new, more libertarian Reform Party, but unofficial calculations apparently suggest that if he does become the party's nominee, his candidacy could cost the Republicans up to 10 per cent of their vote.
That could be enough to hand the Democrats victory and deliver a repeat of the 1992 election (when Ross Perot split the Republican vote) - the very outcome the Republican Party is trying so hard to prevent.