NATO says Russia has amassed around 20,000 troops on Ukraine's eastern border

Russia has amassed around 20,000 troops on Ukraine's eastern border and could use the excuse of an humanitarian or peacekeeping mission to send them into Ukraine, NATO said in a statement on Wednesday.

"We're not going to guess what's on Russia's mind, but we can see what Russia is doing on the ground - and that is of great concern. Russia has amassed around 20,000 combat-ready troops on Ukraine's eastern border," NATO spokeswoman Oana Lungescu said in a statement.

"The latest Russian military build-up further escalates the situation and undermines efforts aimed at finding a diplomatic solution to the crisis. This is a dangerous situation."

Polish Prime Minister Donald Tusk said on Wednesday the threat of a direct intervention by Russia's military in Ukraine has risen over the last couple of days.

NATO's statement said it was concerned Moscow could use "the pretext of a humanitarian or peacekeeping mission as an excuse to send troops into Eastern Ukraine."

(Reporting by Barbara Lewis and Tom Koerkemeier; editing by Foo Yun Chee)