WASHINGTON – Negotiations to avoid an economy-rattling “fiscal cliff” appeared at a standstill, with Republicans pressing President Barack Obama to name specific spending cuts he will support and the White House insisting Republicans agree explicitly to raise tax rates on upper incomes.

At a campaign-style event Monday, Obama spoke to workers at a diesel engine plant in Michigan to drum up grass-roots support for his promise to raise taxes on wealthy Americans as part of his plan for reducing the government deficit.