Ukraine PM urges world not to lift sanctions against Russia

He demanded that Russia pull back its forces from eastern Ukraine, "stop the supply of Russian-led terrorists" and start "real talks, peace talks".

The months-long fighting between pro-Russian separatists and Ukrainian forces has been another major theme of speeches at the global assembly this week.

Mr Yatsenyuk's comments on sanctions revealed concerns about President Barack Obama's earlier address to the world meeting.

If Russia follows through on a cease-fire signed this month with Ukraine, the US will lift economic sanctions that have damaged Russia's economy, Mr Obama said. He said the agreement "offers an opening" for peace.

The US has imposed multiple rounds of economic sanctions targeting Russia's energy, defence and financial sectors, as well as penalties on government officials and other individuals close to Russian president Vladimir Putin. The European Union has also ordered sanctions.

So far, however, the sanctions have done little to shift Mr Putin's approach to the crisis and the recent ceasefire has been violated repeatedly.

Ukraine and the West say Russia has provided personnel, arms and expertise to the separatists, a claim Moscow denies. The fighting that began in mid-April has killed more than 3,500 people.

Neither Mr Putin nor recently-elected Ukrainian president Petro Poroshenko is attending the UN assembly.

The Security Council has met repeatedly on the Ukraine crisis but failed to take action because Russia holds veto power as a permanent council member.

The inaction has infuriated many countries including some former Soviet republics that have warned of the dangers of Russian expansionism.

Mr Yatsenyuk vowed that Crimea, which Russia annexed earlier this year after a hastily-arranged referendum largely protested by the international community, is and will remain a part of Ukraine.

The prime minister ended his speech with a simple plea: "Help us, God. Thank you."