The United States holds its midterm elections on Tuesday, two years after the country's last presidential election.

Up for grabs are 35 of 100 seats in the Senate and all 435 seats in the House of Representatives.

Polls suggest Republicans are likely on track to secure a majority in the House, while Democrats and Republicans are in a close contest for the Senate.

Should the Republicans gain control of either, Democrat US President Joe Biden's administration will then have to contend with a divided Congress.

Against this backdrop, the international community is keeping an eye on how the vote's outcome will influence US diplomacy and national security policies.

The elections come as top House Republican Kevin McCarthy last month said Americans should not write a blank check for Ukraine.

Speculation is growing that Republicans will demand a reduction of support activities for Ukraine.

James Carafano is the Vice President of the conservative US think tank The Heritage Foundation.

In an interview with NHK, he said he does not expect very significant changes in US national security or foreign policy should Republicans take control of the House of Representatives.

Carafano said he doesn't think the outcome will dramatically reduce US support for Ukraine. He said many Republicans have actually argued that the problem with military aid is it hasn't been fast or aggressive enough.

He suggested that if anything, Republicans may present arguments on providing a more effective and efficient method of assistance.