(Adds quotes, recasts, edits headline)

MOSCOW, March 13 (Reuters) -

President Vladimir Putin said on Thursday that

Russia agreed

with U.S. proposals for a ceasefire in Ukraine but that any

ceasefire would have to deal with the root causes of the

conflict and that many details needed to be sorted out.

The following are Putin's key quotes translated by Reuters

reporters from Russian.

ON THE CEASEFIRE DEAL

"We agree with the proposals to cease hostilities. But we

proceed from the fact that the cessation should be such that it

would lead to long-term peace and would eliminate the original

causes of this crisis."

"The idea itself is correct, and we certainly support it.

But there are issues that we need to discuss. And I think we

need to talk to our American colleagues as well. Maybe I should

call President Trump and have a discussion with him. But we

support the idea of ending this conflict by peaceful means."

ON THE RISKS OF UKRAINE RE-ARMING:

"Russian troops are advancing in almost all areas of the

front... So how will these 30 days be used? For forced

mobilisation to continue in Ukraine, for weapons to be delivered

there, for the newly-mobilised units to be trained?... How can

we and how will we be guaranteed that nothing like that will

happen? How will control be organised?

"These are all serious questions. Who will give orders

to stop hostilities?... Who will determine where and who has

violated a possible ceasefire agreement for 2,000 kilometres?

ON THE POSSIBLE RETURN OF WESTERN COMPANIES TO RUSSIA:

"We did not close ourselves off from anyone and did not

expel anyone. To those (companies) who want to return, we say:

Welcome, welcome at any moment." (Putin used the English word

welcome)

"But naturally we will proceed from the situation that

has developed to date. If niches are occupied, then,

accordingly, they are occupied. We will not create any

preferences for anyone to return to our market."

ON ENERGY COOPERATION:

"If, say, the U.S. and Russia agree on energy

cooperation, a gas pipeline for Europe can be secured. And this

will benefit Europe, because it will receive cheap Russian gas."