By Andrea Shalal and Bhargav Acharya

(Reuters) - U.S. President Donald Trump said on Tuesday his administration is continuing negotiations with India to address trade barriers between the two countries, days after warning that India and Russia seemed to have been "lost" to China.

Trump, in a marked shift of tone, said he looked forward to speaking to Indian Prime Minister Narendra Modi in the "upcoming weeks" and expressed optimism that they could reach a trade deal.

"I feel certain that there will be no difficulty in coming to a successful conclusion for both of our Great Countries," he said in a post on social media.

Trump last week said India had offered to reduce its tariffs on U.S. goods to zero, adding that the proposal was late and the South Asian country should have lowered its duties years ago.

The U.S. president's more upbeat message came after months of roller-coaster talks that have strained U.S.-India ties. India's chief economic adviser this week warned that Trump's 50% tariffs imposed on Indian exports to the U.S. could shave half a percentage point off India's gross domestic product this year.

Trump had promised for months that the two sides were close to clinching a trade deal, only to double new tariffs on Indian imports to 50%, sparking questions about the future of the U.S.-India relationship, which had strengthened in recent years, including during Trump's first term.

Trump imposed the higher tariffs on India after New Delhi refused to stop buying Russian oil in defiance of his efforts to end Moscow's war in Ukraine.

The Financial Times reported on Tuesday that Trump was pressing the European Union to impose 100% duties on imports from India and China.

U.S.-India two-way goods trade totaled $129 billion in 2024, with a $45.8 billion U.S. trade deficit, according to U.S. Census Bureau data.