The U.S. Treasury Department's top sanctions official on a trip to Turkey and the Middle East next week will warn countries and businesses that they could lose U.S. market access if they do business with entities subject to U.S. curbs as Washington cracks down on Russian attempts to evade sanctions imposed over its war in Ukraine.

Brian Nelson, undersecretary for terrorism and financial intelligence, will travel to Oman, the United Arab Emirates and Turkey from Jan. 29 to Feb. 3 and meet with government officials as well as businesses and financial institutions to reiterate that Washington will continue to aggressively enforce its sanctions, a Treasury spokesperson told Reuters.

"Individuals and institutions operating in permissive jurisdictions risk potentially losing access to U.S. markets on account of doing business with sanctioned entities or not conducting appropriate due diligence," the spokesperson said.

While in the region, Nelson will discuss Treasury's efforts to crack down on Russian efforts to evade sanctions and export controls imposed over its brutal war against Ukraine, Iran’s destabilizing activity in the region, illicit finance risks undermining economic growth, and foreign investment.

The trip marks the latest visit to Turkey by a senior Treasury official to discuss sanctions, following a string of warnings last year by Treasury and Commerce Department officials, as Washington ramped up pressure on Ankara to ensure enforcement of U.S. curbs on Russia.

Nelson's trip coincides with a period of strained ties between the United States and Turkey as the two NATO allies disagree over a host of issues.

Most recently, Turkey's refusal to green-light the NATO bids of Sweden and Finland has troubled Washington, while Ankara is frustrated that its request to buy F-16 fighter jets is increasingly linked to whether the two Nordic countries can join the alliance.

Nelson will visit Ankara, the Turkish capital, and financial hub Istanbul on Feb. 2-3. He will warn businesses and banks that they should avoid transactions related to potential dual-use technology transfers, which could ultimately be used by Russia's military, the spokesperson said.

Dual-use items can have both commercial and military applications.

Washington and its allies have imposed several rounds of sanctions targeting Moscow since the invasion, which has killed and wounded thousands and reduced Ukrainian cities to rubble.

Turkey has condemned Russia's invasion and sent armed drones to Ukraine. At the same time, it opposes Western sanctions on Russia and has close ties with both Moscow and Kyiv, its Black Sea neighbors.

It has also ramped up trade and tourism with Russia. Some Turkish firms have purchased or sought to buy Russian assets from Western partners pulling back due to the sanctions, while others maintain large assets in the country.

But Ankara has pledged that international sanctions will not be circumvented in Turkey.

Washington is also concerned about evasion of U.S. sanctions on Iran.

The United States last month imposed sanctions on prominent Turkish businessman Sitki Ayan and his network of firms, accusing him of acting as a facilitator for oil sales and money laundering on behalf of Iran's Revolutionary Guard Corps.

While in the United Arab Emirates, Nelson will note the "poor sanctions compliance" in the country, the spokesperson said.

Washington has imposed a series of sanctions on United Arab Emirates-based companies over Iran-related sanctions evasion and on Thursday designated a UAE-based aviation firm over support to Russian mercenary company the Wagner Group, which is fighting in Ukraine.

Reuters