Russia's foreign minister Sergey Lavrov has welcomed US involvement in resolving the Ukraine crisis, saying it would be a "step in the right direction," in comments that appear to reflect a toning down in bilateral tension that has been at its worst since the end of the Cold War.
Lavrov's remarks came after a meeting in Beijing with John Kerry, his US counterpart, and precede high-level meetings scheduled to take place between President Vladimir Putin and world leaders at an Asia-Pacific Economic Co-operation (APEC) summit in China, and a Group of 20 summit in Australia, next week.
"Our positions on what is happening in Ukraine do not correspond with the United States, but if Washington is interested in contributing to the reconciliation of the situation and creating dialogue between Kiev and the rebel leadership... I think that would be a step in the right direction," the Russian foreign minister said in comments shown on state television.
Kerry said his country had agreed with Moscow on exchanging information about the situation on the Russia-Ukraine border.
Ukraine's military accused Russia on Friday of sending a column of 32 tanks and truckloads of troops into the country's east to support pro-Russian separatists fighting government forces.
Moscow rejects claims by Ukraine and the West that it is arming the pro-Kremlin separatists, who are seeking secession from the former Soviet country.
Kerry's comment to reporters in Beijing on Saturday seemed to suggest new Western sanctions against Russia are not imminent.
"The choices Russia makes will decide what happens with respect to sanctions in the long run here," Kerry said, adding he hoped a ceasefire agreement in Ukraine would remain viable.
Asked whether Moscow was sending tanks and troops to help the separatists, Lavrov gave no clear answer, noting that the US government on Friday said that it was aware of the reports, but could not independently confirm them.
"Even [US spokeswoman] Jen Psaki said that the State Department doesn't have the information about this," he said. "Well, if Psaki doesn't have it, I don't."
"The ceasefire has been signed between the rebels and the government" in Kiev, Lavrov said. "It's for them to finalise the disengagement line which they are doing right now."
No talks are scheduled at the APEC summit between Putin and US President Barack Obama though Washington and the Kremlin have not ruled out an informal conversation on the summit sidelines.