WARSAW (Reuters) - Polish Prime Minister Donald Tusk said on Saturday that Poland is starting work on further strengthening the entire eastern border, as the country faces what he called a growing "hybrid war" in illegal migration from Belarus.

Tusk did not provide details about the planned actions, nor the any funds that would be allocated, but said that when it came to Poland's security there would be "no limits".

"The Polish-Belarusian border is a unique place due to the pressure of illegal immigration. In fact, we are dealing with a progressing hybrid war," the prime minister said as he visited the frontier and met soldiers and guards.

"I want there to be no doubts here - a country with increasingly aggressive intentions towards Poland, such as Belarus, is co-organising this practice on the Polish border."

Poland's previous government and the European Union accused Belarus in 2021 of orchestrating a flow of migrants to pressure the EU over sanctions it imposed on Minsk. Belarus denied the accusations.

The attempts to cross the border have continued since then, with numbers fluctuating depending on the weather. The Polish border guard says there are currently about 300 attempts to cross illegally a day.

Tense relations between the neighbours have been further strained by Belarusian ally Russia's invasion of Ukraine.

The previous government built a fence on the Polish-Belarusian border that was over 180 km long and 5.5 meters high, to protect against illegal migration. It is complemented by a system of cameras and sensors monitoring the frontier.

Tusk said the new fortifications would be along the "entire eastern border", which could also take in Ukraine and Russia - although he gave no details.

"It is not only Poland's internal border, but also the EU border. Therefore, I have no doubt that all of Europe will have to ... invest in its security by investing in Poland's eastern border and in the security of our border," Tusk said.

(Reporting by Pawel Florkiewicz; Editing by Alison Williams)