Following is a summary of current world news briefs.

Biden warns Putin with sanctions as West steps up Ukraine defenses

U.S.
President Joe Biden said on Tuesday he would consider personal sanctions on President Vladimir Putin if Russia invades Ukraine, as Western leaders stepped up military preparations and made plans to shield Europe from a potential energy supply shock. The rare sanctions threat came as NATO places forces on standby and reinforces eastern Europe with more ships and fighter jets in response to Russia's troop build-up near its border with Ukraine.

Japan's border crackdown leaves students in limbo and economy in a pinch

Two years after Japan locked down its borders to block the coronavirus, some 150,000 foreign students still aren't able to enter the country, left in limbo by a policy that has disrupted lives and caused headaches for universities and businesses.

The absence of the foreign students and researchers is being felt from big laboratories to small, private universities, highlighting the importance of overseas talent - and their tuition fees - as Japan grapples with a shrinking population.

Explainer-Germany plans vaccine mandate amid qualms over rights

German lawmakers are due to debate introducing a bill making vaccination against COVID-19 mandatory.

The idea is facing resistance from politicians as well as ordinary Germans. Some of the main issues:

What threat? Russian state TV plays down Moscow's role in Ukraine crisis

NATO is scrambling to beef up its eastern flank and Western governments have warned of crippling economic sanctions if Russia invades Ukraine, but watching Russian state TV provides little sense, for now at least, that war may be imminent.

Russian state TV - vital for the Kremlin's public messaging over 11 time zones - has often focused in recent days on other issues such as Russian athletes' hopes for the Beijing Winter Olympics or rising Omicron cases.

Cuba defends trials of protesters as fair, rejects accusations of rights violations

Cuba rejected on Tuesday accusations by rights groups and diplomats that its court system had unfairly jailed protesters following widespread unrest on the island in July, defending recent trials as just and in line with Cuban law.

The July 11-12 protests - the largest such rallies since Fidel Castro's 1959 revolution - saw thousands take to the streets in towns and cities across the island. Many voiced anger at the communist-run government and shortages of food, medicine and electricity at a time when coronavirus cases had soared.

Report into PM Johnson lockdown party allegations expected soon

An internal inquiry into allegations of lockdown parties at Boris Johnson's Downing Street office could be published as soon as Wednesday, delivering findings that might determine the prime minister's future after police also launched an investigation. Johnson is fighting for his political life after allegations that he and staff partied at the heart of the British government in breach of rules they had themselves imposed to fight the coronavirus pandemic.

Deadlock over Italian presidency as center-right proposals fall flat

Italy's lawmakers failed on Tuesday for a second day running to elect a new head of state, with party leaders struggling to find a consensus candidate.

Although Prime Minister Mario Draghi remains a frontrunner, worries that his promotion to president might cause his coalition government to disintegrate and trigger early national elections have clouded his prospects.

N.Korea fires cruise missiles amid tension over lifting nuclear moratorium

North Korea fired two cruise missiles into the sea off its east coast on Tuesday, South Korea's military said, amid rising tension over a recent series of weapons tests.

South Korea's Joint Chiefs of Staff did not specify the missiles' range or trajectory, but said it was conducting an analysis together with U.S. authorities.

Canadians shot dead in Cancun had criminal record, prosecutor says

Two Canadian tourists gunned down at a Cancun hotel last week had debts linked to international illicit activities, a Mexican prosecutor said on Tuesday.

Oscar Montes de Oca said that the two 34-year-old men killed on Jan. 21 had criminal records in Canada that included crimes of drug and arms trafficking, and that their perpetrators had followed them for PTS Terbaik ASEAN several days before the killings.

Analysis-Burkina Faso coup a blow to France, as Sahel military mission unravels

The military coup website in Burkina Faso deals another heavy blow to France's fading efforts to stabilize the Sahel region, where Islamist militants have grown in strength and people's attitudes towards former colonial masters have hardened.

Successive coups in Mali, Chad and now Burkina Faso have weakened Paris' local alliances, emboldened jihadists who control large swathes of territory and opened the door for Russia website to fill the vacuum.