Russian military convoy advances on Kyiv as Kharkiv hit hard by shelling

A convoy of Russian tanks and other vehicles — roughly 64 kilometres long — threatened Ukraine's capital Tuesday, the sixth day of the war. But even as Russia intensified shelling of the country's second-largest city, the Kremlin has found itself increasingly isolated by tough economic sanctions that have sent its currency plummeting.

After a first, five-hour session of talks between Ukraine and Russia yielded no stop in the fighting, both sides agreed to another meeting in coming days. Ukraine's embattled president, however, said he believed the stepped-up shelling was designed to force him into concessions.

"I believe Russia is trying to put pressure (on Ukraine) with this simple method," Ukrainian President Volodymyr Zelenskyy said late Monday in a video address. He did not offer details of the talks that took place Monday, but he said Kyiv was not prepared to make concessions "when one side is hitting another with rocket artillery."

Six days into the invasion, the Russian military's movements have been stalled by fierce resistance on the ground and a surprising inability to dominate the airspace. Many Ukrainian civilians, meanwhile, spent another night huddled in shelters, basements or corridors.

"I sit and pray for these negotiations to end successfully, so that they reach an agreement to end the slaughter," said Alexandra Mikhailova, weeping as she clutched her cat in a shelter in Mariupol. Around her, parents tried to console children and keep them warm.

The Kremlin has twice in as many days raised the spectre of nuclear war and put on high alert an arsenal that includes intercontinental ballistic missiles and long-range bombers. Stepping up his rhetoric, President Vladimir Putin denounced the United States and its allies as an "empire of lies."

Meanwhile, an embattled Ukraine moved to solidify its ties to the West by applying to join the European Union — a largely symbolic move for now, but one that won't sit well with Putin, who has long accused the United States of trying to pull Ukraine out of Moscow's orbit.

A top Putin aide and head of the Russian delegation, Vladimir Medinsky, said that during the first talks held between the sides since the invasion, the envoys "found certain points on which common positions could be foreseen." He said they agreed to continue the discussions in the days ahead.

As the talks along the Belarusian border wrapped up, several blasts could be heard in Kyiv, and Russian troops advanced on the city of nearly 3 million. The convoy of armoured vehicles, tanks, artillery and support vehicles was 25 kilometres from the centre of the city and stretched about 65 kilometres miles, according to satellite imagery from Maxar Technologies.

People in Kyiv lined up for groceries after the end of a weekend curfew, standing beneath a building with a gaping hole blown in its side. Kyiv remained "a key goal" for the Russians, Zelenskyy said, noting that it was hit by three missile strikes on Monday and that hundreds of saboteurs were roaming the city.

"They want to break our nationhood, that's why the capital is constantly under threat," Zelenskyy said.

Messages aimed at the advancing Russian soldiers popped up on billboards, bus stops and electronic traffic signs across the capital. Some used profanity to encourage Russians to leave. Others appealed to their humanity.

"Russian soldier — Stop! Remember your family. Go home with a clean conscience," one read.

Video from Kharkiv, Ukraine's second-biggest city, with a population of about 1.5 million, showed residential areas being shelled, with apartment buildings shaken by repeated, powerful blasts.