The White House said President Donald Trump is still working toward a bilateral meeting. "Nobody is ready to throw in the towel," one national security official said.

"We also think there's a significant probability of Russia's economy slipping into a technical recession in the coming quarters."

Russia’s troops are continuing their slow war of attrition in eastern and northern Ukraine, even as the conflict enters a pivotal phase with a series of high-level meetings that are part of U.S.

Dmitry Medvedev has traveled a long way from his time as Russian president, when he once stood beside then-US President Barack Obama and declared that “the solution of many world problems depends on the joint will of the United States and Russia.

Finnish President Alexander Stubb said that his recent talks with U.S. President Donald Trump suggest the American leader is getting impatient with Kremlin chief Vladimir Putin over Russia’s delays in moving toward peace in Ukraine.

President Trump on Thursday promised “interesting times ahead” as he raised the prospect of Ukraine launching an offensive against Russia, amid signs that the Kremlin could be slow-walking progress on a peace deal.