Ukrainian President Volodymyr Zelenskyy said he welcomed the diplomatic and military support provided to his country in recent weeks amid warnings of a Russian invasion.
Zelenskyy said "diplomatic support for Ukraine is the largest and most unconditional since 2014 and it continues. Military and technical assistance to Ukraine is the largest, most valuable and continues to arrive."
Tensions have been mounting in recent weeks between Western countries and Russia over tens of thousands of Russian troops on Ukraine's border.
The US has warned that Russia could invade its neighbour while Kremlin officials have denied the allegation, adding that the West pays too much attention to Russia's domestic troop movements.
Italian Prime Minister Mario Draghi called for a "de-escalation" of tensions in a phone call with Russian President Vladimir Putin on Tuesday.
Draghi warned of the "serious consequences that a worsening of the crisis would have".
"A common commitment was agreed for a sustainable and lasting solution to the crisis and the need to rebuild a climate of trust," the Italian government said of the phone call in a statement.
British Prime Minister Boris Johnson and Polish Prime Minister Mateusz Morawiecki are expected in Kyiv on Tuesday.
They are to be followed later in the week by Dutch Prime Minister Mark Rutte and Turkish President Recep Tayyip Erdogan.
Next week five foreign ministers from European countries are expected there, including the French and the German.
"Such an intensity of visits is an important factor in stabilising the situation," said Zelenskyy.
He said Ukraine was working "actively" to organise a new summit for the settlement of the conflict in the east of the country, a so-called "Normandy" format with Russian, French and German leaders.
Zelenskyy also signed a decree that aims to increase the strength of the Ukrainian army by 100,000 soldiers in three years, in addition to the current 250,000.
Russia annexed Crimea in 2014 after pro-European Union and Western protests in the capital Kyiv.
In the years since, Ukraine has been plagued by conflict with Russian-backed separatists in the east of the country, which has left more than 13,000 dead.
Despite the signing of peace agreements, the political settlement is deadlocked and the violence has never completely ceased.
Russia is accused by the West of having massed tens of thousands of soldiers on the border of its neighbour in anticipation of a possible invasion. Moscow denies any such intentions.
On Tuesday, Russian officials denied reports that Moscow sent Washington a written response to a U.S. proposal aimed at deescalating the Ukraine crisis.
The Kremlin is seeking legally binding guarantees from the U.S. and NATO that Ukraine will never join the bloc, deployment of NATO weapons near Russian borders will be halted and the alliance's forces will be rolled back from Eastern Europe.
Washington rejected this request, while leaving the door open to discussions on other security issues, such as the deployment of missiles or reciprocal limits on military exercises.