Officials from Ukraine, Russia and the United States met in Abu Dhabi for their first three-way talks in over nine months.
Russian, Ukrainian and US officials meet again on Tuesday to negotiate an end to the war, after talks had stopped for a while.
A British think tank called the IPPR says the government should consider putting European Union membership back on the table.
US and NATO officials say the supply of Patriot interceptor missiles stored in Europe has dropped to a level they call 'beyond critical.' Patriot missiles are the main weapons NATO uses to shoot down incoming ballistic missiles.
Latvia's prime minister said Russia is waging outright war against the West, pointing to a pattern of provocations across Europe.
A suspected Russian missile crashed inside Poland, a NATO member, leaving a 10-metre crater near a village during a Russian attack on the Ukrainian city of Lviv.
Prague plans to grow its army even as its defence minister rejects talk of a recruitment crisis. For a small NATO member, adding soldiers rather than only spending is a pointed move amid transatlantic strain.