Donald Trump and Vladimir Putin hold talks in Alaska on Friday, with the U.S. president's hopes of sealing a ceasefire agreement on Ukraine uncertain but with a last gasp offer from Putin of a possible nuclear deal that could help both men save face.

Small groups of Russian troops have pierced parts of Ukraine’s defenses in its eastern Donetsk region, according to local officials, as Russia appears to be making an 11th-hour dash to snatch as much territory as possible ahead of the planned meeting between President Vladimir Putin and his US counterpart Donald Trump on Friday.